Embodiments of the subject matter disclosed herein correspond to turbomachine assemblies, transfer ducts for connecting turbomachines, and methods of arranging ducts.
In the field of “Oil & Gas”, it is common to fluidly connect two or more turbomachines in cascade.
This is the case, for example, when a fluid needs to be compressed at high compression ratio: instead of using a single (and very long) multistage compressor, two (shorter) multistage compressors are used and connected in cascade, as shown in
A configuration such as the one shown in
The “back-to-back” configuration is advantageous as, during operation of the assembly, the axial thrust exerted by one of the two machines may be (substantially) balanced by the axial thrust of the other one of the two machines and does not load axially the bearings of the machines; the “back-to-back” configuration is even more advantageous when magnetic bearings are used for supporting the two machines as magnetic bearings can not withstand high axial thrust.
In a turbomachine assembly with “back-to-back” configuration, the fluid connection between the first and second machines requires a long piping as the outlet of the first machine and the inlet of the second machine are remote from each other.
In the exemplary assembly of
An external transfer piping like the one of
Therefore, there is a general need for improved solutions to the problem of fluidly connecting turbomachines arranged in “back-to-back” configuration, especially for subsea applications in the field of “Oil & Gas”.
More in general, there is a need for improved solutions to the problem of arranging distinct and separate ducts in the same space.
An important idea is to locate the transfer duct inside the casing.
Another important idea is to shape the transfer duct as an annular duct.
Another important idea is to provide one pipe-shape seat inside the transfer duct.
Another important idea is to provide one or more struts inside the transfer duct.
First embodiments of the subject matter disclosed herein relate to turbomachines assembly.
In the general, the turbomachine assembly comprises:
a first turbomachine having an inlet, an outlet and a rotary shaft,
a second turbomachine having an inlet, an outlet and a rotary shaft,
a transfer duct fluidly connecting the outlet of the first turbomachine to the inlet of the second turbomachine, and
a casing housing the turbomachines and the transfer duct;
the turbomachines are located adjacent to each other so that the outlet of the second turbomachine is close to the outlet of the first turbomachine and the inlet of the second turbomachine is remote from the outlet of the first turbomachine; the outlet of the second turbomachine has an end portion shaped like a cochlea; the transfer duct has an annular shape, and surrounds the end portion of the outlet of the second turbomachine.
Second embodiments of the subject matter disclosed herein relate to transfer ducts for fluidly connecting the outlet of a first turbomachine to the inlet of a second turbomachine.
In general, the transfer duct consists of a single duct; the single duct has an annular shape around an axis; the single duct develops at the begin at least partially radially, in the middle substantially axially and at the end at least partially radially; the single duct has one pipe-shaped seat for housing at least partially another duct crossing it; the single duct has one or more struts for structural reinforcement.
Third embodiments of the subject matter disclosed herein relate to methods of arranging a first and a second distinct and separate ducts, the first duct being designed for feeding a first fluid in an axial direction and the second duct being designed for feeding a second fluid in a radial direction.
In general, the method comprises:
configuring the first duct as a single annular duct so to define an internal space,
configuring the second duct as a single spiral duct,
positioning the second duct inside the internal space defined by the first duct,
prolonging the single spiral duct so to cross the single annular duct.
The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate exemplary embodiments of the present invention and, together with the detailed description, explain these embodiments. In the drawings:
The following description of exemplary embodiments refers to the accompanying drawings.
The following description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.
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.
a first turbomachine 210 having an inlet 211, an outlet 212 and a rotary shaft 213 (with axis 214),
a second turbomachine 220 having an inlet 221, an outlet 222 and a rotary shaft 223 (with axis 224),
a casing 230 housing turbomachines 210 and 220 and transfer duct 240.
The turbomachines 210 and 220 are located adjacent to each other so that the outlet 222 of the second turbomachine 220 is close to the outlet 212 of the first turbomachine 210 and the inlet 221 of the second turbomachine 220 is remote from the outlet 212 of the first turbomachine 210; in particular, they are in the so-called “back-to-back configuration”. According to this embodiment, shafts 213 and 223 are exactly coaxial and a single axis 204 corresponds to both axis 214 of shaft 213 and axis 224 of shaft 223. According to this embodiment, shafts 213 and 223 are mechanically coupled together through a rigid joint (not highlighted in the figure); alternatively, for example, a unique solid shaft may be used.
The outlet 222 of the second turbomachine 220 has an end portion 225 shaped like a cochlea (i.e. a spiral duct).
The transfer duct 240 is a single duct with an annular shape (both internally and externally) and surrounds the end portion 225 of the outlet 222 of the second turbomachine 220; in particular, the transfer duct 240 surrounds axially and radially (i.e. completely) not only portion 225 but the whole second turbomachine 220 (only small zones close to the shaft 223 of the second turbomachine 220 are not surrounded—see right side and left side in
The transfer duct 240 is completely internal to the casing 230.
The transfer duct 240 develops at the begin 241 at least partially radially (getting far from its axis 204, i.e. increasing its distance) and in the middle 242 substantially axially and at the end 243 at least partially radially (getting close to its axis 204, i.e. decreasing its distance)—see
As it is clear from
Assembly 200 has one inlet duct, in the form of a pipe 231 with a flange 232, and one outlet duct, in the form of a pipe 233 with a flange 234; both ducts, i.e. pipes 231 and 233, protrude from the casing 230.
The end portion 225 of the outlet 222 of the second turbomachine 220 is fluidly connected to the outlet duct 233 of the assembly through a connection duct 235. The connection duct 235 passes through the transfer duct 240; more specifically, it goes from one side, i.e. the internal wall, to the other side, i.e. the external wall, of the transfer duct 240. The connection duct 235 is a prolongation of the cochlea 225 and is partially housed in a pipe-shaped seat of the transfer duct 240 (see also
The radial distance between the transfer duct and the axis of the shaft of the second machine increases along the begin 441 of the transfer duct; this allows to overcome the second turbomachine.
The area of the cross-section of the transfer duct increases along the begin 441 of the transfer duct (in other words, the transfer duct widens); this allows to reduce the speed (especially its axial component) of the fluid flowing inside the transfer duct and consequently to recover some pressure; in other words, the initial portion of the transfer duct acts similarly to an outlet cochlea of a turbomachine.
The portion of the transfer duct at the begin 441 surrounds the end portion 425 of the outlet of the second turbomachine completely in the radial direction and completely, only on one side, in the axial direction.
Portion 525 is to be fluidly connected to an outlet duct of the assembly; this is the purpose of connection duct 535 (corresponding to duct 235 of
Connection duct 535 passes through transfer duct 540; more specifically, it goes from one side, i.e. the internal wall, to the other side, i.e. the external wall, of the transfer duct 540. Connection duct 535 is a prolongation of the cochlea-shape duct 525. Transfer duct 540 has one pipe-shaped seat 544 housing partially (or totally) connection duct 535 crossing it.
Transfer duct 540 has one strut 545 (or more than one, for example two or three or four or five or six or seven or . . . ) for structural reinforcement; such structural element is a (relatively) short solid element that may be arranged radially or substantially radially.
Heat insulating material (for example in the form of layers) may be place between the transfer duct and the cochlea-shape duct and/or between connection duct and transfer duct.
As it is clear for a person skilled in the art from the above description, a first and a second distinct and separate ducts have been arranged; the first duct is designed for feeding a first fluid in an axial direction and the second duct is designed for feeding a second fluid in a radial direction.
According to such arrangement, the following steps are provided:
configuring the first duct as a single annular duct so to define an internal space,
configuring the second duct as a single spiral duct,
positioning the second duct inside the internal space defined by the first duct, and
prolonging the single spiral duct so to cross the single annular duct.
Such arrangement is particularly effective when the first and second fluid flows come from outlets of turbomachines; in fact, it allows to minimize load losses and/or heat losses and/or heat exchanges.
From the application point of view, the embodiments of the present invention are very flexible.
According to a specific embodiment (in “back-to-back configuration”), the first and second turbomachines mentioned before may be for example compressors or pumps, multistage centrifugal machines (the number of stages of the first machine may be equal to or different from the number of stages of the second machine); but the assembly may comprise further machines, for example an engine such as an electric motor or a turbine; especially when an electric motor is used, the compressors or pumps are fluidly well isolated from the engine.
According to another specific embodiment (in “back-to-back configuration”), the first turbomachine is a compressor or pump, a multistage centrifugal machine, the second turbomachine is a turbine, a multistage machine.
All the machines of the assembly are housed inside the same casing.
In general, the rotary shafts of these machines are mechanically coupled together; in
In an embodiment of the present invention is in turbomachine assemblies designed to be installed subsea.
This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention 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 if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Number | Date | Country | Kind |
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CO2014A000033 | Oct 2014 | IT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/073978 | 10/16/2015 | WO | 00 |