Patent Application
20120171052
1. Technical Field
Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for efficiently providing a motor and a compressor in a single casing.
2. Discussion of the Background
In the petrochemical industry, booster pumps or compressors may be located at intervals along a liquid-products or gas pipeline to boost the pressure of the flowing gas or liquid to keep it moving toward its destination. Booster pumps or compressors may also be used in other pipelines to move gas or liquid to and through various processes associated with petrochemical exploration, refinement and transport. Examples of a booster compressor are an in-line centrifugal compressor and an axial compressor that are used to move gaseous petrochemicals or byproducts through pipelines. These pipeline boosters can be used upstream (during exploration and production), midstream (during processing, storage and transportation) or downstream (during natural gas/petrochemical refining, transmission and distribution) in a petrochemical process.
To move natural gas or other gases, centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy.
In some cases, a standard casing size can house a different number of impellers to optimize performance in terms of efficiency, compression ratio and operating range. Compressor casings can be made of forged steel to maximize material strength and metallurgical stability. Vibration reduction may be provided by bearings positioned at both casing ends. Dry gas seals may be used to prevent gas leakage. Floating bushing oil seals may also be used.
Various motors can be used to drive the booster pumps or compressors, including electric motors, gas turbines or other motors. For example, a booster station may couple a turbine, operating as a gas generator, with a power turbine to drive the booster compressor. Alternatively, an electric motor may be used, especially in pipelines.
As noted above, various industries use a compressor that is driven by an electrical motor. As these two machines are complex and also connected to each other, when parts of the compressor fail or need maintenance, the entire machine needs to be shut down, and the compressor needs to be dissemble piece by piece until the operator reaches the failed part or the part that needs maintenance. This process is tedious and time consuming as a conventional compressor has many parts.
An example of a turbomachine that reduces the assembly/disassembly time comparative with the machine shown in
In order to connect or disconnect the compressor cartridge 102 and the electric motor 104, a retractable cover 201 is operated, as shown 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 motor compressor system in which the motor is configured to activate the compressor. The system includes a common casing; a motor cartridge housing a motor, the motor cartridge detachably placed inside the common casing; and a compressor cartridge housing a compressor detachably connected to the motor, the compressor cartridge detachably placed inside the common casing.
According to another exemplary embodiment, there is a motor cartridge system that includes a motor cartridge configured to be detachably provided inside a common casing; and a motor housed within the motor cartridge and configured to be detachably connected to a compressor, the compressor configured to compress gas for transport in a gas pipeline.
According to still another exemplary embodiment, there is a motor compressor system in which a motor is configured to activate a compressor. The system includes a common casing; a motor cartridge housing the motor, the motor cartridge detachably provided inside the common casing; a compressor cartridge housing the compressor detachably connected to the motor, the compressor cartridge detachably provided inside the common casing; a mechanical connector connecting a motor shaft of the motor to a compressor shaft of the compressor within the common casing; magnetic bearings provided in the motor around the motor shaft; and a pipe configured to connect a downstream gas supply pipe or an upstream gas supply pipe connected to the common casing to a motor inlet duct of the motor cartridge so as to provide the gas to cool the motor.
According to still another exemplary embodiment, there is a method of repairing a system including a compressor cartridge having a compressor, the system also including a motor cartridge having a motor, the system configured to receive a gas, compress the gas, and eject the compressed gas. The method includes turning off the motor; closing or bypassing a gas flow through the compressor; disconnecting the motor from the compressor by disconnecting a mechanical joint connecting a motor shaft of the motor to a compressor shaft of the compressor; and disconnecting and removing the motor cartridge and/or the compressor cartridge from the common casing. The compressor cartridge and the motor cartridge are provided inside the common casing.
According to yet another exemplary embodiment, there is a method of compressing gas. The method includes receiving the gas into a motor compressor system from a pipeline duct at a first pressure, the motor compressor system including a compressor driven by a motor having magnetic bearings; compressing the gas with the compressor; and ejecting the compressed gas to an output pipeline at a second pressure higher that the first pressure.
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 permanent magnet compressor and a motor assembly having a common casing. However, the embodiments to be discussed next are not limited to these systems, but may be applied to other systems that combine two machines in a common casing.
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, components of a motor are provided in a motor cartridge and components of a compressor are provided in a compressor cartridge to form a machine assembly. The compressor cartridge and the motor cartridge are independently from each other and connected to each other inside a common casing. Thus, when either parts of the motor or the compressor need to be accessed or changed, the entire cartridge including the part may be removed from the common casing and another new cartridge may be slided back into the common casing for a fast restarting of the machine assembly.
Shafts 409 and 410 of the compressor cartridge 401 and the motor cartridge 402 may be connected to each other by a Hirth connection 404A and a pin 404B. A Hirth connection is used to connect two pieces of a shaft together and is characterized by teeth that mesh together on the end faces of each half shaft. In other embodiments, other connectors between the shafts of the centrifugal compressor cartridge 401 and the motor cartridge 402 may be used as long as the connection may be connected or disconnected without the need of maintenance personnel to enter inside the common casing 403. Such connections may be a magnetic connector or a flexible connector or a Hirth connection or a flange or others types of connections known in the art.
In one exemplary embodiment, there are one or more sets of magnetic bearings 408. The magnetic bearings 408 permit relative motion with very low friction and/or mechanical wear. Also, because magnetic bearings do not require lubricants, there is no risk of contamination from the lubricants, and there is no need to replenish said lubricants. The internal surfaces of the common casing 403 are preferably configured to permit the sliding of the motor cartridge 402 and the compressor cartridge 401 in opposite directions during the installation phase.
Turning to the compressor cartridge 401 shown in
The compressor cartridge 401 is configured to have an inlet duct 450 that is configured to be connected to an upstream gas supply for providing the gas to an inlet 452 of the common casing 403 that feeds the compressor. The compressor cartridge 401 also has an outlet duct 454 that is configured to be connected to a downstream gas pipe. The outlet duct 454 is connected to an outlet 456 of the common casing 403 that receives the pressurized gas from the compressor. Pipe 428 may be connected to the inlet duct 450 or the outlet duct 454 for providing gas for cooling parts of the motor.
In an exemplary embodiment shown in
Advantages of the modular permanent magnetic motor compressor system shown in
The turbomachine shown in
Gas flows from pipeline 502 through station 500 as illustrated by the arrows included in
Compressor 506 includes at least one stage of compression that increases a pressure of gas flowing therethrough. Compressor 506 includes: a housing with an inner surface and an outer surface, the inner surface defining a cooling plenum and a compressor intake plenum. There may also be a gas supply header coupled to the discharge header 510 such that a portion of the outlet gas flow is diverted to the motor 508 for cooling via expansion within the motor 508. If the motor 508 includes a gas turbine and a combustor, the booster may include a gas supply header coupled to the suction header 504 such that a portion of the inlet gas flow stream upstream from the housing outer surface is diverted from the suction header and is channeled to the gas turbine as a fuel source.
An advantage of one or more embodiments discussed above is that the turbomachine is simple to upgrade while being part of the plant as the upgrade include replacing the compressor or motor cartridge of the novel machine with a new one in order to better match the changed plant needs.
The disclosed exemplary embodiments provide a motor compressor system that includes self-contained compressor cartridge connectable to a self-contained motor cartridge, the compressor cartridge and the motor cartridge each configured to be installed in a common casing. 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 |
|---|---|---|---|
| MI2010A002466 | Dec 2010 | IT | national |
