This invention is directed generally to turbine engines, and more particularly to pilot nozzle support systems of a turbine engine fuel assembly.
Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, a fuel injection system, and a turbine blade assembly for producing power. Combustors often operate at high temperatures that may exceed 2,500 degrees Fahrenheit. Typical turbine combustor configurations expose components of turbine engine fuel systems to these high temperatures. Turbine engines fuel systems typically include pilot nozzles for injecting fuel into a combustion chamber. Conventionally, pilot nozzles have been bolted to a support housing to attach the pilot nozzles to turbine engines. A typical support housing consists of a base having an orifice extending through the base for receiving the pilot nozzle. The pilot nozzle is bolted directly to the base. During use of this conventional configuration, the pilot nozzle has a natural frequency that falls within an excitation zone, which thereby subjects the pilot nozzle to destructive vibrations.
Other conventional support assemblies have included sleeves coupled to the orifices of the support housings to increase the natural frequencies of the pilot nozzles such that the natural frequencies are outside excitation zones to reduce, if not eliminate, destructive vibrations. Typically, the sleeves have been welded to the support housings. However, the welds have not had a sufficiently long life as a result of the vibrations inherent in operating turbine engines. Thus, a need exists for a more efficient, reliable pilot nozzle support system.
This invention relates to an automatic recovery pilot nozzle support system for a pilot nozzle of a fuel system of a turbine engine. The support system is configured to support a pilot nozzle with a sleeve and to increase the natural frequency of the pilot nozzle outside an excitation range to avoid destructive vibrations. The support system includes a sleeve that maintains contact with a support housing at substantially all times of operation of a turbine engine. Should the sleeve ever lose contact with the support housing during operation of a turbine engine, an insulative film of air may form between the sleeve and the support housing causing the sleeve to increase in temperature relative to the support housing. The sleeve, as a result, expands and regains contact with the support housing.
The support system may include a support housing having at least one orifice, a hollow sleeve positioned in the orifice of the support housing and having an outer diameter that is greater than an inner diameter of the orifice such that an interference fit exists between the support housing and the sleeve. The hollow sleeve may be adapted to receive a nozzle positioned in the hollow sleeve and generally aligned with the hollow sleeve. The hollow sleeve may also have first and second sections in which the first section may have a diameter that is greater than a diameter of the second section. The second section may be configured to contact and support a nozzle. The sleeve may also include a retention protrusion, which may be in the form of a ring and referred to as a collar, on an end of the sleeve for preventing the sleeve from being inserted completely through the support housing.
The support housing may include a collar extending from a base of the support housing towards an unsupported end of the sleeve to a point that is less than half a total length of the sleeve from the base. The collar may also extend a distance of about one third of a total length of the sleeve from the base. The collar may also form a portion of the orifice extending through the support housing and may have an inner diameter that is less than an outer diameter of the sleeve.
The support system may be assembled by first exposing the sleeve to a temperature less than ambient temperature to reduce the temperature of the sleeve to a temperature sufficient to reduce the diameter of the sleeve such that the sleeve may be inserted into the orifice in the support housing. The sleeve may then be inserted into the support housing, and the temperature of the sleeve allowed to return to ambient temperature. As the temperature of the sleeve increases toward ambient temperature, the sleeve increases in diameter and can form an interference fit with the support housing. A pilot nozzle may be inserted into the sleeve in a variety of manners to position the pilot nozzle in the sleeve.
During operation, the support housing supports a pilot nozzle within a combustion chamber of a turbine engine. As the engine runs, the combustion chamber, and as a result, the support system and pilot nozzle, increase in temperature. As the sleeve of the support system increases in temperature and expands, the sleeve maintains contact with the support housing. Should the sleeve lose contact with the support housing, a film of insulative air may develop between the sleeve and the support housing causing the temperature of the sleeve to increase relative to the support housing. The increase in temperature of the sleeve causes the sleeve to expand and regain contact with the support housing.
An advantage of this invention is that the support system has an automatic support system configured such that should a sleeve of a pilot nozzle support system loose contact with a support housing, the sleeve will rapidly heat, expand, and regain contact with the support housing, thereby reestablishing an interference fit with, and the support of, the support housing.
Another advantage of this invention is the support system eliminates welds of conventional support systems that are typically exposed to extreme temperature gradients for attaching a sleeve of a pilot nozzle support system to a support housing.
Yet another advantage of this invention is the support system may be assembled in a time efficient manner with few assembly steps.
These and other embodiments are described in more detail below.
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.
This invention is directed to an automatic recovery pilot nozzle support system 10 usable in a turbine engine. As shown in
The support housing 14, as shown in
As shown in
As shown in
The support system 10 may be assembled by shrinking the sleeve 16 by exposing the sleeve 16 to a temperature less than ambient temperature to cause thermal contraction of the material forming the sleeve 16. In at least one embodiment, the sleeve 16 may be exposed to liquid nitrogen, other appropriate substance, or a reduced temperature climate condition to reduce the temperature of the sleeve 16. The temperature of the sleeve 16 may be reduced to such an extent that the outer diameter 26 of the sleeve 16 may be reduced to be less than the inside diameter 28 of the orifice 20 in the support housing 14. The sleeve 16 may then be inserted into the orifice 20 in the support housing 14. An interference fit may be established between the sleeve 16 and the support housing 14 by enabling the sleeve to return to ambient temperature. In alternative embodiments, the temperature of the support housing 14 may be increased to increase the size of the orifice 20 so that the sleeve 16 may be inserted into the orifice 20. The pilot nozzle 12 may be inserted into the sleeve 16 and attached to the sleeve 16 using any appropriate method.
During operation of the turbine engine, the temperature of the pilot nozzle 12 and automatic recovery pilot nozzle support system 10 increase together with the turbine engine. The interference fit between the sleeve 16 and the support housing 14 may be maintained for substantially all, if not all, time in which the turbine engine is operating. For instance, the interference fit may be maintained through all transient trips and at all engine running conditions, such as, but not limited to, 30 percent base load with either cold or heated fuel, base load with either cold or heated fuel, and other operating conditions.
The automatic recovery aspect of the support system 10 enables the sleeve 16 to maintain contact with the support housing 14 during operating conditions in a turbine engine. For instance, when an interference fit is maintained between the sleeve 16 and the support housing 14, as shown in
The interference fit may be sized and the materials forming the support housing 14 and the sleeve 16 chosen such that during operation, the interference fit is maintained between the support housing and the sleeve 16 but the stresses are minimized. Thus, the inner diameter 28 of the orifice 20 may be smaller than the outer diameter 26 of the sleeve 16, but not to such an extent that destructive stresses are created in the sleeve 16 or the support housing 14, or both. In fact, during operation, a portion of the sleeve 16 in contact with the support housing 14 may relax during thermal cycle operation to prevent the sleeve 16 from undergoing plasticity.
The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.
Number | Name | Date | Kind |
---|---|---|---|
4852803 | Gaskell | Aug 1989 | A |
5343694 | Toborg et al. | Sep 1994 | A |
5465571 | Clark | Nov 1995 | A |
6032457 | McKinney et al. | Mar 2000 | A |
6038862 | Melman et al. | Mar 2000 | A |
6053432 | Stevens | Apr 2000 | A |
6351948 | Goeddeke | Mar 2002 | B1 |
6357222 | Schilling et al. | Mar 2002 | B1 |
6666029 | Ryan | Dec 2003 | B2 |
6705087 | Ohri et al. | Mar 2004 | B1 |
6708495 | Calvez et al. | Mar 2004 | B2 |
20020139121 | Cornwell et al. | Oct 2002 | A1 |
20030024249 | Akagi et al. | Feb 2003 | A1 |
20040006990 | Stuttaford et al. | Jan 2004 | A1 |
20040006991 | Stuttaford et al. | Jan 2004 | A1 |
20040006992 | Stuttaford et al. | Jan 2004 | A1 |
20040006993 | Stuttaford et al. | Jan 2004 | A1 |
20040020210 | Tanaka et al. | Feb 2004 | A1 |
20040025494 | Vache et al. | Feb 2004 | A1 |
20040045295 | Wiebe et al. | Mar 2004 | A1 |
20040050058 | Ohri et al. | Mar 2004 | A1 |
20040055311 | Swinford et al. | Mar 2004 | A1 |
Number | Date | Country | |
---|---|---|---|
20060026966 A1 | Feb 2006 | US |