U.S. patent application number 13/508383 was filed with the patent office on 2012-10-04 for gas compressor assembly.
Invention is credited to Patrick Van Der Span.
Application Number | 20120251351 13/508383 |
Document ID | / |
Family ID | 41600305 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120251351 |
Kind Code |
A1 |
Van Der Span; Patrick |
October 4, 2012 |
Gas Compressor Assembly
Abstract
A gas compressor assembly for compressing a gas includes a rotor
having a rotational axis, a motor section and a compressor section
arranged along the rotational axis of the rotor. The gas is
supplied via an inlet. A first motor passageway directs the gas
from the inlet to the motor section for cooling the motor section.
A compressor passageway directs the gas from the motor section to
the compressor section. The assembly also includes a gas-tight
housing to enclose the rotor, a bearing section, the motor section,
and the compressor section. The motor section includes a motor and
a stator. The inlet is arranged such that a majority the gas
flowing through the inlet is directed to the motor section through
the first motor passageway wherein the gas cools the motor section
before compression of the gas, to provide increased cooling of the
motor and the stator.
Inventors: |
Van Der Span; Patrick;
(Hengelo, NL) |
Family ID: |
41600305 |
Appl. No.: |
13/508383 |
Filed: |
November 10, 2010 |
PCT Filed: |
November 10, 2010 |
PCT NO: |
PCT/EP10/67177 |
371 Date: |
May 7, 2012 |
Current U.S.
Class: |
417/366 |
Current CPC
Class: |
F04D 29/701 20130101;
F04D 25/0606 20130101; F04D 29/058 20130101; F04D 25/0686 20130101;
F04D 17/122 20130101; F04D 29/5806 20130101; F04D 29/584
20130101 |
Class at
Publication: |
417/366 |
International
Class: |
F04B 39/06 20060101
F04B039/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2009 |
EP |
09014133.4 |
Claims
1-13. (canceled)
14. A gas compressor assembly for compressing a gas, comprising: a
rotor having a rotational axis, a motor section and a compressor
section arranged along the rotational axis of the rotor, an inlet
to supply the gas, a first motor passageway to direct the gas from
the inlet to the motor section for cooling the motor section, a
compressor passageway to direct the gas from the motor section to
the compressor section, a gas-tight housing to enclose the rotor, a
bearing section , the motor section, and the compressor section,
wherein the motor section comprises a motor and a stator, and
wherein the inlet is arranged such that a majority the gas flowing
through the inlet is directed to the motor section through the
first motor passageway wherein the gas cools the motor section
before compression of the gas, to provide increased cooling of the
motor and the stator.
15. The gas compressor assembly according to claim 14, wherein the
inlet is positioned adjacent to the side of the motor section
distant from the compressor section.
16. The gas compressor assembly according to claim 14, wherein the
bearing section is arranged along the rotational axis of the rotor
at the side of the motor section distant from the compressor
section , wherein the inlet is connected to the bearing section
through a first bearing passageway to supply the gas for cooling
the bearing section.
17. The gas compressor assembly according to claim 16, wherein the
bearing section includes a second bearing passageway to direct the
gas from the bearing section to the motor section.
18. The gas compressor assembly according to claim 14, wherein all
the gas supplied through the inlet is used for cooling the motor
section.
19. The gas compressor assembly according to claim 14, wherein the
gas compressor assembly further comprising a second motor
passageway to supply the gas to a motor gap between the rotor and a
stator for cooling the motor section.
20. The gas compressor assembly according to claim 14, wherein the
first motor passageway provides the gas radially outside of the
stator for cooling the stator of the motor section.
21. The gas compressor assembly according to claim 14, wherein the
inlet is connected to supply gas to a separation unit adapted to
separate at least one of a liquid and solid particle from the gas
before providing it for cooling.
22. The gas compressor assembly according to claim 21, wherein the
separation unit comprises an annular chamber positioned
circumferentially around the axis of the rotor, wherein the gas is
rotated inside the chamber such that at least one of the liquid and
solid particle is separated from the gas.
23. The gas compressor assembly according to claim 22, wherein the
annular chamber includes a outer section and an inner section for
the passage of the gas, wherein the outer section receives the gas
from the inlet and the inner section is adapted to supply the gas
received from the outer section to the motor section.
24. The gas compressor assembly according to claim 22, wherein the
annular chamber further includes a barrier element positioned
between the outer section and inner section, wherein the barrier
element deflects at least of the liquid and solid particles from
the outer section to the inner section around the barrier
element.
25. The gas compressor assembly according to claim 22, wherein the
separation unit further includes a drain line extending out of the
compressor assembly to expel the separated liquid and solid
particle from the gas.
26. The gas compressor assembly according to claim 21, wherein the
separation unit is positioned on the inlet side between the inlet
and the motor section in the compressor assembly.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International
Application No. PCT/EP2010/067177, filed Nov. 10, 2010 and claims
the benefit thereof. The International Application claims the
benefits of European application No. 09014133.4 EP filed Nov. 11,
2009. All of the applications are incorporated by reference herein
in their entirety.
FIELD OF INVENTION
[0002] The present invention relates to a gas compressor assembly,
such a gas compressor is known from U.S. Pat. No. 7,156,627 B2.
BACKGROUND OF INVENTION
[0003] It is frequently necessary to compress a gas to a great
extent, for example to store a large quantity of gas in a tank or
the like, or to urge a significant quantity of gas through a
pipeline or other industrial applications. Generally motors are
provided for driving the compression mechanism to compress the gas.
Conventionally, the motor in such compression mechanism produces
significant heat during operation. Providing adequate motor
cooling, without sacrificing energy efficiency of the compression
system, continues to challenge designers of gas compression
systems.
[0004] U.S. Pat. No. 7,156,627 B2 discloses a gas compressor
assembly for such gas compression which usually comprises a rotor
with an axis of rotation, a centrifugal compressor for compressing
a gas, and an electric motor arranged on a common rotor shaft, a
first bearing section and a second bearing section including
bearings arranged in the vicinity of both ends of the rotor shaft
to support the rotor. The gas compressor assembly herein includes
an inlet positioned between the motor and the compressor to supply
the gas to the compressor.
[0005] The compressor compresses the gas and the compressed gas is
passed through a filter to remove the impurities present in the gas
and is then provided to the motor, the first bearing section and
the second bearing section through separate passageways running
from the compressor for cooling these sections. Disadvantageously,
the temperature of the compressed gas herein may be high which
decreases the capacity of the cooling gas to cool the motor and the
bearing sections.
[0006] The document DE 200 11 217 U1 discloses a compressor
assembly having a first compressor and a second compressor arranged
on opposite sides of a motor, wherein the main mass-flow of the
inlet gas is first fed to the first pressure compressor, and, after
compression by the first compressor, the main mass-flow of the gas
is fed to the second compressor, while only a small portion of this
flow is conducted as a coolant gas to the motor.
[0007] Document U.S. Pat. No. 2,542,016 A deals with an explosion
proof dynamoelectric machine cooling its motor section by fans
sucking an air flow through an open housing along its motor
section.
[0008] Documents WO 01/20168 A1 and WO 2007/134405 A1 both disclose
open housing blowers, wherein between the blower-stages a motor for
driving the blowers is arranged.
SUMMARY OF INVENTION
[0009] It is an object of the invention to improve motor cooling
efficiency of the gas compressor assemblies.
[0010] This problem is solved by the features of the independent
claim(s).
[0011] The underlying idea of the invention is to increase the
cooling of the motor section by supplying a majority of the gas
directly to the motor section before getting compressed. The
compression of the gas increases the pressure of the gas by
expending energy leading to an increase in the temperature of the
gas. Thus providing the uncompressed gas helps to improve the
cooling of the motor section as the uncompressed gas has higher
capacity to carry-over the heat away from the motor section.
[0012] According to a preferred embodiment, the inlet is positioned
adjacent to the side of the motor section distant from the
compressor section. This reduces the length of the motor passageway
thereby making the design compact.
[0013] According to a preferred embodiment, the gas compressor
assembly further includes a bearing section arranged along the
rotational axis of the rotor at the side of the motor section
distant from the compressor section, wherein the inlet is connected
to the bearing section through a first bearing passageway to supply
the gas for cooling the bearing section. This helps to provide a
gas with relatively lesser temperature to the bearing such that the
gas takes in more heat to provide increased cooling to the
bearings, which in turn prevents the degradation of bearings due to
extra heat.
[0014] According to a preferred embodiment, the bearing section
includes a second bearing passageway to direct the gas from the
bearing section to the motor section. This helps to provide
additional gas flow to increase the rate of gas flowing through the
motor section for cooling of the motor.
[0015] According to another preferred embodiment, the gas
compressor assembly further comprising a second motor passageway to
direct the gas to a motor gap between the rotor and a stator for
cooling the motor section. The passageway provides for supplying
the cooling gas to the space between the rotor and the stator so as
to effectively cool the motor.
[0016] According to a preferred embodiment, the first motor
passageway supplies the gas radially outside the stator for cooling
the motor section. This helps to establish direct gas contact with
the stator to transfer heat from the stator to ensure desired
cooling of the motor section.
[0017] According to a preferred embodiment, the inlet is arranged
so as to channel the gas to the compressor section through the
motor section. This helps to cool the motor section before
compression of the gas, thereby providing increased cooling of the
motor and stator.
[0018] According to a preferred embodiment, all the gas supplied
through the inlet is used for cooling the motor section. This
provides for increased cooling of the motor section and eliminates
the need for additional cooling devices such as fans, radiators or
the like.
[0019] According to a preferred embodiment, the inlet is connected
to a separation unit to separate at least one of a liquid and solid
particle from the gas before providing for cooling. This helps to
prevent any damage of the motor or bearings due to the presence of
corrosive particles. Also it increases the efficiency of the
compressor as the gas supplied to the compressor section is
substantially free of impurities.
[0020] According to another preferred embodiment, the separation
unit comprises an annular chamber positioned circumferentially
around the axis of the rotor for the passage of the gas, wherein
the gas is rotated inside the chamber such that at least one of the
liquid and solid particles is separated from the gas. The annular
chamber is simple in design with a big radius which yields high
centrifugal forces leading to a good separation of the impurities
from the gas. Also, this does not require any auxiliary device for
operation, which in turn provides for cleaning the gas in a
cost-effective manner.
[0021] According to another preferred embodiment, the annular
chamber includes an outer section and an inner section for the
passage of the gas, wherein the outer section is connected to
receive the gas from the inlet to and the inner section is adapted
to supply the purified gas to the motor section. This helps to
separate the impurities from the gas at the outer section itself,
thereby helps to supply the gas substantially free of impurities to
the motor section, which in turn prevents the damage of the motor
and also increases its efficiency.
[0022] According to another preferred embodiment, the annular
chamber further includes a barrier element positioned between the
outer section and the inner section, wherein the barrier element
deflects the liquid and solid particles from the outer section to
the inner section. By this deflection liquid and other solid
particles can be separated from the gas to be provided for
cooling.
[0023] According to yet another preferred embodiment, the
separation unit further includes a drain line extending out of the
compressor to expel the separated liquid and solid particle from
the gas. This drain line isolates the separated particles and
liquid from the assembly, thereby preventing the back-mixing of the
particles with the gas.
[0024] According to yet another preferred embodiment, the
separation unit is positioned on the inlet side in the compressor
assembly between the inlet and the motor section. This provides a
compact design and helps to reduce the length of the flow path of
the gas.
[0025] According to yet another preferred embodiment, the assembly
further includes a gas-tight housing enclosing all the components
of the assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The present invention is further described hereinafter with
reference to illustrated embodiments shown in the accompanying
drawings, in which:
[0027] FIG. 1 shows a schematic overview in a cross-section of a
gas compressor assembly according to an embodiment of the
invention; and
[0028] FIG. 2 illustrates a schematic top view of a separation unit
according to an embodiment herein.
DETAILED DESCRIPTION OF INVENTION
[0029] Various embodiments are described with reference to the
drawings, wherein like reference numerals are used to refer to like
elements throughout. In the following description, for purpose of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of one or more embodiments. It may
be evident that such embodiments may be practiced without these
specific details.
[0030] FIG. 1 shows a schematic overview in a cross-section of a
gas compressor assembly 10 according to an embodiment of the
invention. The gas compressor assembly 10 comprises of a rotor 12
having an axis 13 of rotation, a bearing section 14, a motor
section 15, and a compressor section 16. These sections are
arranged in the order referred herein along the axis 13 of the
rotor 12.
[0031] Here, the bearing section 14 is arranged along the
rotational axis 13 of the rotor 12 at the side of the motor section
15 distant from the compressor section 16. The bearing section 14
includes a plurality of active magnetic bearings 18 for supporting
the rotor 12.
[0032] The assembly 10 herein further includes a common gas-tight
housing 17 enclosing the rotor 12, the bearing section 14, the
motor section 15, and the compressor section 16. The assembly 10
further includes another bearing section 38 enclosed with the gas
tight housing 17. The bearing sections 14, 38 are generally
disposed at the axial end sections of the rotor 12.
[0033] The gas compressor assembly 10 herein further includes an
inlet 20 designed to provide an unregulated gas input to the
assembly. The inlet 20 is positioned adjacent to the side of the
motor section 15 distant from the compressor section 16. The gas 11
is drawn through the inlet 20 and is directed through various
passages to cool the internal components of the gas compressor
assembly 10 in a predetermined sequence to optimize the cooling
efficiency and operating life of the assembly 10.
[0034] The inlet 20 through which the gas 11 enters the gas
compressor assembly 10 is placed adjacent to the bearing section 14
for providing the gas 11 to the different sections in the assembly
10. The inlet 20 can be an aperture formed on the compressor
housing 17 or can be a line extending from external components to
provide gas 11 to the compressor assembly 10.
[0035] The inlet 20 is connected to the motor section 15 through a
first motor passageway 22 to provide the main flow of gas 11 to the
motor section 15 for cooling the motor section 15. The gas 11
supplied through the first motor passageway 22 is directed radially
outside a stator 19 in the motor section 15. The motor section 15
further includes a motor gap 26 that extends longitudinally between
the stator 19 and the rotor 12. Here, the gas 11 from the inlet 20
is supplied to the motor gap 26 through a second motor passageway
23 radially extending from the first motor passageway 22 to cool
the motor section 15 to an acceptable operation temperature.
[0036] In addition, the inlet 20 herein is connected to the bearing
section 14 through a bearing passageway 21 for guiding the gas 11
from the gas flow path to the bearing section 14. The gas 11
supplied to the bearing section 14 is directed through the bearing
gaps 25 between the active magnetic bearings 18 for cooling the
active magnetic bearings 18. The gas 11 from the bearing section 14
is further directed to the motor section 15.
[0037] The inlet 20 is arranged such that majority of the gas 11,
for instance 60% to 90%, supplied through the inlet 20 is passed to
the motor section 15 for cooling the motor section 15. The gas 11
is supplied directly to the motor section 15, before getting
compressed at the compressor section 17. The heat carrying capacity
of the uncompressed gas is more, which helps to effectively carry a
substantial amount of heat from the motor section 15, thereby
reducing the recycling flows. Here, the gas 11 supplied through the
inlet 20 has a pressure sufficient enough to provide the required
flow rate through the assembly 10.
[0038] As shown in the FIG. 1, the gas compressor 10 includes a
separation unit 27 placed at the inlet 20 side between the inlet 20
and motor section 15. The separation unit 27 removes the liquid or
other solid particles present in the gas 11 before providing it for
cooling. The inlet 20 is connected to an annular chamber 28 of the
separation unit 27. The gas 11 to be filtered enters through the
inlet 20 into the annular chamber 28 where it is rotated at a high
speed around the axis 13 of the rotor 12. This provides for
separating the liquid, solid particle or other impurities which may
present in the gas 12 before supplying for cooling to the motor
section 15 and bearing section 14. The separated liquid and solid
particles are discharged from the annular chamber 28 by a drain
line 29 extending out of the gas compressor assembly 10.
[0039] In the embodiment of FIG. 1, the motor section 15 and the
compressor section 16 are arranged in a fluid-connecting manner in
the assembly 10. Thus the gas 11 from the motor section 15 is
directed to the compressor section 16 through a compressor
passageway 24 for compression. The compressor section 16 includes a
compressor 30 which may be a compressor known in the art that is
used for gas compression applications, such as axial compressors,
radial compressors, and the like. The compressor 30 is connected to
a gas outlet 31, through which compressed gas 11 exits the gas
compressor assembly 10.
[0040] For ease of installation and retrieval, the motor section 15
and the compressor section 16 can be accommodated in a single
housing. Such an arrangement is particularly useful for subsea
applications in which easy installation and retrieval are
important.
[0041] The first and second motor passageways 23, 24 provide
sufficient space for the gas 11 to flow through such that the gas
streaming through the motor section 15 is not significantly
restricted by the passageways 23, 24. That is the passageways are
large enough to handle the stream of gas 11 without producing
pressure build up on the inlet 20 side or a pressure drop on the
side of the motor section providing gas to the compressor section
16. This provides the benefit of a continuous and relatively
uniform supply of gas 11 to the compressor section 16 for
compression.
[0042] FIG. 2 illustrates a schematic top view of a separation unit
27 according to an embodiment herein. The separation unit 27 herein
is an accessorial unit which can be positioned in the assembly 10
to remove the liquid or solid particles from the incoming gas flow
before the gas 11 is directed for cooling the motor section 15 or
other internal components.
[0043] In the separation unit 27 of FIG. 2, inlet 20 of the gas
compressor 10 is connected to the separation unit 27 to provide the
gas 11. The gas 11 from the inlet 20 is then fed to an annular
chamber 28 in the separation unit 27. The gas 11 flowing through
the chamber 28 may include traces of liquid, air or other type of
gases containing dust or other particle impurities suspended
therein with the impurities to be cleansed from the gas.
[0044] The annular chamber 29 herein is divided to an outer section
32 and an inner section 33. Here both sections 32, 33 are separated
from each other by a barrier element 34 placed between the inner
and outer sections 32, 33. The barrier element 34 herein is
preferably in the shape of an annular ring. This geometry is
aligned with the flow of gas and thereby reduces the pressure loss
of the gas flow.
[0045] Once the gas 11 is fed to the annular chamber 28, it is
brought into rapid rotation in a direction along the rotational
axis of the rotor 12 in the outer section 32. During this
rotational movement, a large part of the liquid or other solid
particles are flung out against the inner wall 35 of the annular
chamber 28 owing to the centrifugal force where they gets collected
and consequently drains out by gravity. The collected liquid or
particles can be drained off via a drain line 29 without gas being
mixed into an appreciable extent. The gas 11 is rotated preferably
at a rotational speed of 20,000 to 35,000 revolutions per minute.
The gas 11 which is substantially free of the impurities is then
passed on the inner section 33 to be circulated to the motor
section 15.
[0046] The separation unit 27 further includes bearing passageway
21 and motor passageways 22, 23 extending from the annular chamber
28 to supply the filtered gas 11 to the bearing section 14 and
motor section 15 for cooling. The annular chamber 28 herein
combines the function of separation of liquid or other solid
particles and distribution of the gas to be compressed over the
circumference of the rotation axis 10 in one compact component.
[0047] The separation unit 27 of FIG. 2 can be placed
circumferentially around the axis 13 of rotation of the rotor 12
and can be secured thereto by a securing means 36 such as nuts or
the like. The separation unit 27 is simple in design with no moving
parts to operate and is substantially easy to install in the gas
compressor assembly 10. Also it requires no power to operate and
starts working as soon as the gas to be treated is introduced.
Moreover, it provides a minimum maintenance operation where the
solid deposits can be removed by washing the annular chamber 28
with water or by running a liquid capable of dissolving the
solid.
[0048] The dimensions of the annular chamber 28 determine the gas
flow rate and the residence time required for the given separation
process. The dimensions of the annular chamber 28 can be determined
experimentally so that the higher separation efficiency can be
obtained.
[0049] The separation unit 27 design herein provides for preventing
gas turbulence and back-mixing, which in turn prevents re-entering
of liquid or other particles and results in very high separation
efficiencies for most industrial applications. The separation unit
27 is suitable for use with additional pressurization, vacuuming,
cooling condensation, etc with little or no design
modifications.
[0050] In the embodiment herein, the inlet is arranged prior to the
motor section. This helps to provide for filtering the gas before
providing for cooling, thereby avoiding the need for separate
scrubber and additional gas/fluid systems.
[0051] The gas compressor according to the invention finds
extensive applications where higher pressure or lower volumes of
gas is required. For instance, in pipeline transport of purified
natural gas to move the gas from the production site to the
consumer, in submarines, to store air for later use in displacing
water from buoyancy chambers, for adjustment of depth, in petroleum
refineries, natural gas processing plants, petrochemical and
chemical plants, and similar large industrial plants for
compressing intermediate and end product gases, in turbochargers
and superchargers to increase the performance of internal
combustion engines by increasing mass flow and the like.
* * * * *