Methods and apparatus for transporting natural gas through a pipeline

1. A compressor assembly for use in transporting natural gas, said assembly comprising:

a natural gas compressor comprising at least one stage of compression, that increases a pressure of natural gas flowing therethrough;

a permanent magnet-type super-synchronous motor coupled to said natural gas compressor for powering said compressor;

a housing comprising an inner surface and an outer surface, said inner surface defines a cooling plenum and a compressor intake plenum, said compressor and said permanent magnet-type super synchronous motor both positioned within said housing;

a suction header for supplying gas from a source upstream from said compressor assembly to said compressor assembly, said suction header coupled to said housing outer surface for channeling an inlet gas flow stream into said compressor intake plenum; and

a cooling gas supply header coupled to said suction header such that a portion of the inlet gas flow stream upstream from said housing outer surface is diverted from said suction header and is channeled to said cooling plenum to facilitate cooling said permanent magnet-type super-synchronous motor.

2. A compressor assembly in accordance with claim 1 wherein said compressor comprises at least one of an axial-type compressor, a centrifugal-type compressor, and a ducted fan-type compressor.

3. A compressor assembly in accordance with claim 1 wherein said permanent magnet-type super-synchronous motor comprises a plurality of high-energy density magnets.

4. A compressor assembly in accordance with claim 1 wherein said compressor and said motor are coupled together via a rotatable coupling extending between said compressor and said motor.

5. A compressor assembly in accordance with claim 1 wherein said housing comprises a plurality of piping connections that facilitate fluid flow into said compressor and fluid flow out of said compressor.

6. A compressor assembly in accordance with claim 1 wherein said housing comprises a plurality of housing elements sealingly coupled to each other.

7. A compressor assembly in accordance with claim 6 wherein said motor and said compressor are coupled together and positioned in said housing such that at least a portion of gas supplied to said compressor is channeled to said motor to facilitate cooling said motor.

8. A compressor assembly in accordance with claim 7 wherein said compressor is axially and radially supported via a plurality of magnetic bearings.

9. A method to facilitate transporting natural gas through a pipeline, said method comprising:

receiving natural gas from a first section of the pipeline at a first pressure;

compressing the gas using a compressing device driven by a prime mover that includes a rotor including permanent magnets, the compressing device and the prime mover both enclosed in a housing that includes an inner surface and an outer surface, the inner surface defines a cooling plenum and an intake plenum, the compressed gas being at a second pressure that is greater than the first pressure;

channeling a portion of an inlet gas flow stream from the first section of the pipeline through a suction header into the intake plenum, the suction header for supplying natural gas from a source upstream from the compressing device to the compressing device;

diverting a portion of the inlet gas flow stream, upstream from the housing outer surface, from the suction header through a cooling gas supply header coupled to the housing outer surface to the cooling plenum to facilitate cooling the compressing device; and

discharging the gas at the second pressure into a second section of the pipeline, downstream from the first section of pipeline.

10. A method in accordance with claim 9 wherein receiving the natural gas from a first section of the pipeline comprises using at least a portion of the natural gas to facilitate cooling at least a portion of the prime mover.

11. A method in accordance with claim 9 wherein compressing the gas comprises coupling the compressing device to a permanent magnet-type super-synchronous electric motor.

12. A method in accordance with claim 11 wherein coupling the compressing device to a permanent magnet-type super-synchronous electric motor comprises:

coupling the compressing device and the motor together via a common rotatable shaft; and

positioning the compressing device and the permanent magnet-type super-synchronous motor in a common housing to form a fully enclosed unit such that at least a portion of gas supplied to the housing is channeled to the motor to facilitate cooling the motor.

13. A compressing station for use in transporting natural gas, said compressing station comprising:

a natural gas compressor for increasing a pressure of natural gas being transported;

a piping system for facilitating natural gas transport, said piping system coupled in flow communication to said compressor;

a permanent magnet-type super-synchronous motor coupled to said compressor for powering said compressor;

a housing comprising an inner surface and an outer surface, said inner surface defines a cooling plenum and a compressor intake plenum, said compressor and said permanent magnet-type super synchronous motor both positioned within said housing;

a suction header for supplying gas from a source upstream from said compressing station to said compressing station, said suction header coupled to said housing outer surface for channeling an inlet gas flow stream into said compressor intake plenum;

a cooling gas supply header coupled to said suction header such that a portion of the inlet gas flow stream upstream from said housing outer surface is diverted from said suction header, and is channeled to said cooling plenum to facilitate cooling said permanent magnet-type super-synchronous motor;

a power converter coupled to said motor; and

a speed and torque control system for controlling said motor.

14. A compressing station in accordance with claim 13 wherein said compressor comprises at least one of an axial-type compressor, a centrifugal-type compressor, and a ducted fan-type compressor.

15. A compressing station in accordance with claim 13 wherein said piping system comprises a plurality of piping, a plurality of valves, and a plurality of piping supports.

16. A compressing station in accordance with claim 13 wherein said permanent magnet-type super-synchronous motor comprises high energy density magnets.

17. A compressing station in accordance with claim 13 wherein said motor and said compressor are axially and radially supported via a plurality of magnetic bearings such that at least a portion of gas supplied to said compressor facilitates cooling said motor.

18. A compressing station in accordance with claim 13 wherein said power converter comprises a variable frequency drive (VFD) device wherein said VFD comprises a frequency converter device.

19. A compressing station in accordance with claim 13 wherein said speed and torque control system comprises a variable frequency drive (VFD) device wherein said VFD comprises a frequency converter device.