1. Technical Field
Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for integrating an auxiliary equipment within a gas turbine.
2. Discussion of the Background
Gas turbines are used many industries, from military to power generation. They are used mainly to produce electrical energy. However, some gas turbines are used to propel various vehicles, airplanes, ships, or for other reasons. For example, in the oil and gas market the gas turbines are used to drive compressors and pumps. As shown in
Various auxiliary equipments are provided with the gas turbine, e.g., oil pump for the bearings, compressors, a mechanical accessory (e.g., a gear box) or an electrical equipment (e.g., an electrical starter, a generator or an helper motor, etc). All these components need to be supplied with power for performing their functions. There are many possibilities for supplying the auxiliary equipment with power. Two common arrangements are discussed next. As shown in
An alternative arrangement is illustrated in
Accordingly, it would be desirable to provide systems and methods that avoid the afore-described problems and drawbacks.
According to one exemplary embodiment, there is a gas turbine system having a reduced footprint. The gas turbine system includes a gas turbine configured to produce energy and having a gas turbine shaft; an auxiliary equipment attached to the gas turbine; an overhung shaft of the auxiliary equipment being configured to be attached to the gas turbine shaft; a flexible joint configured to be provided between the shaft of the auxiliary equipment and the gas turbine shaft; and a bearing system having at least two bearing units provided at a first end of the shaft of the auxiliary equipment next to the flexible joint. The second end of the shaft of the auxiliary equipment is free of bearings
According to another exemplary embodiments, there is a gas turbine system having a reduced footprint. The gas turbine system includes a gas turbine configured to produce energy and having a gas turbine shaft; an auxiliary equipment attached to the gas turbine; an overhung shaft of the auxiliary equipment being configured to be attached to the gas turbine shaft; and a bearing system having at least two bearing units provided at a first end of the shaft of the auxiliary equipment and supported by the gas turbine's stator. The second end of the shaft of the auxiliary equipment is free of bearings.
According to still another exemplary embodiment, there is a gas turbine system having a reduced footprint and including a gas turbine shaft shared by a compressor and an expander; an auxiliary equipment having an overhung shaft attached to the gas turbine shaft; a bearing system having at least two bearing units provided at a first end of the shaft of the auxiliary equipment next to the gas turbine shaft. A second end of the shaft of the auxiliary equipment is free of bearings.
According to yet another exemplary embodiment, there is a method for assembling a gas turbine and an auxiliary equipment to form a gas turbine system. The method includes a step of directly connecting to a flexible joint a gas turbine shaft of the gas turbine and a shaft of the auxiliary equipment; and supporting the shaft of the auxiliary equipment with a bearing system only at a first end. A second end of the shaft of the auxiliary equipment is free of bearings.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:
The following description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to the terminology and structure of a gas turbine having an auxiliary equipment. However, the embodiments to be discussed next are not limited to these systems, but may be applied to other systems that require a reduced footprint and less impact on the gas turbine shaft rotordynamic.
Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
According to an exemplary embodiment illustrated in
A casing 112 of the gas turbine 102 includes at least a bearing unit 114 for supporting an end 106a of the shaft 106 and a casing 118 includes at least two bearing units 120a and 120b for supporting the shaft 108 of the auxiliary equipment. The casing 118 may be the casing of the auxiliary equipment 104 or may be part of the casing 112 as will be discussed later. It is noted that according to this embodiment, the shaft 108 of the auxiliary equipment 104 has bearing units only at one end 108a and not to the other end 108b, i.e., an overhung shaft. These novel features are now discussed in more details.
According to an exemplary embodiment illustrated in
A shaft 162 of the auxiliary equipment is provided partially inside the casing 156 of the gas turbine and partially inside a casing 163 of the auxiliary equipment 154. The shaft 162 is configured in such way that only a first end 162a is supported by a bearing system 168. The other end 162b of the shaft 162 has no support, thus the shaft 162 is an overhung shaft. The bearing system 168 includes at least two bearing units 164 and 166 for supporting the shaft 162. These bearing units may be any type of bearings known in the art. The bearing system 168 is provided inside the casing 156 in this embodiment. In one application, the double bearing unit 164 and 166 is a single piece bearing or two individual items spaced axially by a desired distance.
In order to minimize rotordynamic effects on the shaft 158 of the gas turbine 152, a flexible joint 170 is provided between shaft 158 and shaft 162. In one application, the flexible joint 170 is directly coupled to the shaft 158 and the shaft 162. The flexible joint 170 has one or more of the following features. The flexible joint 170 allows the shaft 158 (or the shaft 162) to move along axis X without displacing the shaft 162 (or the shaft 158). Additionally or optionally, the flexible joint 170 allows one shaft to slip relative to the other shaft while in rotation, up to a certain threshold. One or more of these features allow the shaft 162 of the auxiliary equipment to not affect the rotordynamic of the shaft 158 of the gas turbine 152. No gear box is provided between the two shafts and no support is provided for the casing 163 of the auxiliary equipment.
According to another exemplary embodiment illustrated in
According to still another exemplary embodiment, which is illustrated in
One or more advantages of the above noted embodiments are related to a reduction in the footprint of the gas turbine system, as no supporting system is necessary for the auxiliary equipment. It is also noted that the rotordynamic of the shaft of the gas turbine is not affected by the presence of the auxiliary equipment. Proposed embodiments have also the possibility to adopt auxiliary equipments with only one shaft end supported. The flexible joint (e.g., quill shaft) provide the two shafts with a better coupling. The auxiliary equipment may be provided on either side of the gas turbine, e.g., inlet casing on cold side or outlet casing on hot side.
A method for assembling a gas turbine system as discussed above is now discussed with regard to
The disclosed exemplary embodiments provide a system and a method for producing a gas turbine with a reduced footprint and rotordynamic not affected by an auxiliary equipment. It should be understood that this description is not intended to limit the invention. On the contrary, the exemplary embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.
Although the features and elements of the present exemplary embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein.
This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.
Number | Date | Country | Kind |
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CO2011A000017 | May 2011 | IT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2012/059303 | 5/18/2012 | WO | 00 | 11/19/2013 |