U.S. patent application number 14/888499 was filed with the patent office on 2016-03-24 for cooling system.
The applicant listed for this patent is SIEMENS AKTIENGESELLSCHAFT. Invention is credited to UFFE ERIKSEN, SOEREN GUNDTOFT, THORKIL MUNK-HANSEN, CLAUS THYGESEN.
Application Number | 20160084226 14/888499 |
Document ID | / |
Family ID | 48534171 |
Filed Date | 2016-03-24 |
United States Patent
Application |
20160084226 |
Kind Code |
A1 |
ERIKSEN; UFFE ; et
al. |
March 24, 2016 |
COOLING SYSTEM
Abstract
A wind turbine generator cooling system whereby the electrical
generator includes a stator, a rotor, and an air gap between the
stator and the rotor, and the rotor is rotatable in respect to the
stator around an axis of rotation. The generator includes a cavity
that is abutting on the stator in a radial direction, whereby a fan
is connected to the cavity, so that the fan moves air through the
cavity to cool the generator. A duct extends through the cavity in
a mainly axial direction from a first side of the generator to a
second side of the generator to allow the air that moves through
the cavity, that cools the generator, and that collects at least
partially at the first side of the generator, to flow from the
first side of the generator to the second side of the generator to
exit the generator.
Inventors: |
ERIKSEN; UFFE; (HORSENS,
DK) ; GUNDTOFT; SOEREN; (FREDERICIA, DK) ;
MUNK-HANSEN; THORKIL; (GIVE, DK) ; THYGESEN;
CLAUS; (L SBY, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIEMENS AKTIENGESELLSCHAFT |
Munchen |
|
DE |
|
|
Family ID: |
48534171 |
Appl. No.: |
14/888499 |
Filed: |
September 12, 2013 |
PCT Filed: |
September 12, 2013 |
PCT NO: |
PCT/EP2013/068943 |
371 Date: |
November 2, 2015 |
Current U.S.
Class: |
290/55 |
Current CPC
Class: |
Y02E 10/72 20130101;
Y02E 10/722 20130101; H02K 7/18 20130101; H02K 9/04 20130101; F03D
1/00 20130101; F03D 80/60 20160501; Y02E 10/725 20130101; F03D 9/25
20160501; H02K 7/1838 20130101; F05B 2260/64 20130101; F03D 15/20
20160501 |
International
Class: |
F03D 9/00 20060101
F03D009/00; F03D 1/00 20060101 F03D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 22, 2013 |
EP |
13168761.8 |
Claims
1. A wind turbine generator cooling system for a direct driven wind
turbine, wherein an electrical generator comprises a stator, a
rotor, and an air gap between the stator and the rotor, the rotor
being rotatable with respect to the stator around an axis of
rotation, the electrical generator comprising a cavity that is
abutting on the stator in a radial direction, further wherein a fan
is connected to the cavity so that the fan moves air through the
cavity to cool the electrical generator; wherein a duct extends
through the cavity in a mainly axial direction from a first side of
the electrical generator to a second side of the electrical
generator to allow the air that moves through the cavity that cools
the electrical generator, and that collects at least partially at
the first side of the electrical generator; to flow from the first
side of the electrical generator to the second side of the
electrical generator to exit the electrical generator.
2. The wind turbine generator cooling system according to claim 1,
wherein the cavity comprises a first wall to separate an interior
of the cavity from the first side of the electrical generator, and
a second wall to separate the interior of the cavity from the
second side of the electrical generator, further wherein the first
wall and the second wall define the axial ends of the cavity, and
the duct extends through the interior of the cavity from an opening
in the first wall of the cavity to an opening in the second wall of
the cavity.
3. The wind turbine generator cooling system according to claim 1,
wherein the stator comprises a plurality of ducts that connect the
cavity with the air gap in a way that the air from the cavity flows
into the air gap, and along the air gap to the first side and to
the second side of the electrical generator.
4. The wind turbine generator cooling system according to claim 1,
wherein the rotor is arranged radially outward of the stator, and
the stator is attached to a main shaft of the wind turbine, and the
cavity is arranged between the stator and the main shaft.
5. The wind turbine generator cooling system according to claim 1
wherein the wind turbine comprises a nacelle and the electrical
generator is attached to the nacelle, the nacelle comprising a
housing; wherein an air outlet connects an interior of the
electrical generator with an exterior of the wind turbine, the air
outlet being arranged between the housing of the nacelle and the
rotor of the electrical generator to allow the warm air from inside
the electrical generator to exit the wind turbine.
6. The wind turbine generator cooling system according to claim 5,
wherein the air outlet comprises a sealing.
7. The wind turbine generator cooling system according to claim 1,
wherein an air inlet duct is connected to the fan and that a filter
is attached to the air inlet duct so that the air is filtered
before it is blown into the cavity.
8. The wind turbine generator cooling system according to claim 7,
wherein the filter is an aerosol filter.
9. The wind turbine generator cooling system according to claim 5,
wherein the housing of the nacelle comprises an air inlet for air
to enter the nacelle.
10. The wind turbine generator cooling system according to claim 9,
wherein the air inlet to the nacelle comprises a dehumidifier
and/or a filter for aerosols.
11. The wind turbine generator cooling system according to claim 9,
wherein the air inlet of the nacelle is arranged in a back wall of
the housing of the nacelle.
12. The wind turbine generator cooling system according to claim 9,
wherein the air inlet of the nacelle is arranged at a side of the
housing of the nacelle.
13. The wind turbine generator cooling system according to claim 3,
wherein the plurality of ducts in the stator are arranged in the
lamination plates of the electrical generator.
14. The wind turbine generator cooling system according to claim
13, wherein the plurality of ducts in the stator are gaps between
at least two stacks of lamination plates of the electrical
generator.
15. A method comprising: cooling a generator of a wind turbine
using the wind turbine generator cooling system according to claim
1.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to PCT Application No.
PCT/EP2013/068943, having a filing date of Sep. 12, 2013, based off
of European Application No. 13168761.8 having a filing date of May
22, 2013, the entire contents of which are hereby incorporated by
reference.
FIELD OF TECHNOLOGY
[0002] The invention following relates to a wind turbine generator
cooling system.
BACKGROUND
[0003] A wind turbine comprises a nacelle that is rotatable
arranged on top of a tower. A rotor hub that comprises at least one
rotor blade is rotatable attached to the nacelle.
[0004] In a direct driven wind turbine the rotor hub is directly
coupled to the rotor of an electrical generator. The rotation of
the rotor hub is not transferred by a gear.
[0005] The electrical generator comprises a stator and a rotor. The
stator is attached to the stationary part of the nacelle of the
wind turbine. The rotor is arranged rotatable in respect to the
stator of the electrical generator.
[0006] The wind interacts with the rotor blade so that the rotor
hub and the rotor of the electrical generator rotate.
[0007] The generator produces electrical energy. Heat is created in
the stator and the rotor of the electrical generator due to eddy
currents and losses. This excess heat can become so intense that
parts of the generator get damaged. Thus, the generator needs to be
cooled.
[0008] Several concepts to cool the generator are known.
[0009] It is known from EP 1218638 A1 and US 8047774 B2 to cool the
generator with a first cooling fluid and transfer the heat to a
second cooling fluid by the use of a heat exchanger.
[0010] This shows the disadvantage that two cooling circuits with
pumps and a heat exchanger are used. Cooling systems like these use
a lot of electrical energy for the cooling operation.
[0011] EP 2141360 A2 discloses a wind turbine with a tower and a
nacelle with a generator. The generator comprises a stator, a rotor
and a fan. The nacelle is divided into a front part and a rear part
by the generator, the front part and the rear part of the nacelle
are connected by the air gap of the generator, wherein the fan is
blowing air from the rear part of the nacelle through the air gap
to the front part of the nacelle. The air is sucked in through an
opening in the nacelle and is cooling the generator.
[0012] This shows the disadvantage, that the generator divides the
nacelle in a front part and a back part, and that the cooling air
passes the air gap in the generator from the back part to the front
part. Thus an exit for the warm air has to be provided in the front
part of the nacelle, to allow the air to exit the wind turbine.
Thus both sides of the generator are needed for additional the
connection of the cooling system to the generator or for additional
installations of the cooling system, like fans.
SUMMARY
[0013] An aspect relates to providing an improved generator cooling
system.
[0014] A wind turbine generator cooling system for a direct driven
wind turbine is disclosed, whereby the electrical generator
comprises a stator, a rotor, and an air gap between the stator and
the rotor, and the rotor is rotatable in respect to the stator
around an axis of rotation.
[0015] The generator comprises a cavity that is abutting on the
stator in a radial direction, whereby a fan is connected to the
cavity, so that the fan moves air through the cavity to cool the
generator.
[0016] A duct extends through the cavity in a mainly axial
direction from a first side of the generator to a second side of
the generator to allow the air that moves through the cavity, that
cools the generator, and that collects at least partially at the
first side of the generator, to flow from the first side of the
generator to the second side of the generator to exit the
generator.
[0017] The wind turbine generator cooling system for a direct
driven wind turbine cools the generator of the wind turbine using
air as the cooling medium. Air is available in and around a wind
turbine to be used as a cooling medium.
[0018] Thus, no additional cooling medium has to be provided. In
addition air as a cooling medium does not cause a problem when a
leakage occurs.
[0019] The generator of the wind turbine comprises a rotor and a
stator. An air gap is defined between the rotor and the stator of
the electrical generator. The rotor is arranged rotatable in
respect to the stator around an axis of rotation.
[0020] The generator comprises a certain expansion along the axis
of rotation, thus a certain axial length. The rotor and the stator
have a certain distance from the axis of rotation, thus they have a
certain radius.
[0021] During the operation of the wind turbine and thus during the
generation of electrical energy heat is generated in the rotor and
the stator in the vicinity of the air gap.
[0022] Thus, the stator and the rotor increase in temperature due
to the excess heat. During the operation of the wind turbine the
excess heat has to be removed by a cooling system.
[0023] The generator comprises a cavity. The cavity is directly
abutting on the stator, thus it is in direct contact with the
stator. The cavity is abutting on the stator in a radial direction.
In the case of an outer rotor generator the cavity is abutting
radially inward of the stator. In the case of an inner rotor
generator the cavity is abutting on the stator radially outward of
the stator.
[0024] Thus the cavity does not interfere with the air gap or the
rotor of the generator.
[0025] A fan is connected to the cavity. The fan moves air through
the cavity to cool the generator. The fan moves the air through the
cavity either by sucking the air through the cavity or by blowing
the air into the cavity.
[0026] Thus air moves through the cavity. The air is used to cool
the generator of the wind turbine. Thus the cavity is a part of the
cooling system of the generator. The temperature of the air moving
through the cavity increases as the air cools the generator. The
warm air is then released from the generator.
[0027] Thus the generator is cooled by the air.
[0028] The air enters the cavity at a first opening, also called an
air inlet, and exits the cavity at a second opening. The air that
moves through the cavity at least partially collects at a first
side of the generator. The first side of the generator is at one of
the axial ends of the generator.
[0029] A duct extends through the cavity. The duct leads through
the cavity in a mainly axial direction from a first side of the
generator to a second side of the generator. The duct allows air to
flow from the first side of the generator to the second side of the
generator. There the air can exit the generator.
[0030] The air moves through the cavity, cools the generator, and
collects at least partially at the first side of the generator. The
warm air that picked up the heat of the generator flows through the
duct in the cavity to the other side of the generator without
mixing with the air in the cavity, or nearly without increasing the
temperature of the air inside the cavity.
[0031] The air flows through the duct to the second side of the
generator and exits the generator there.
[0032] Thus the fan that moves the air through the cavity, and the
air exit of the generator are arranged at the same side of the
generator.
[0033] Thus only one side of the generator is used to connect the
cooling system to the generator. Thus the other side is not used
for the cooling system. The other side is closed by a cover to
avoid wind, rain, and aerosols to enter the generator of the wind
turbine.
[0034] In addition, the closed side of the generator can be used to
connect the rotor of the wind turbine to the generator, whereby an
interference with connections of the cooling system with the rotor
of the wind turbine is avoided.
[0035] The cavity comprises a first wall to separate the interior
of the cavity from a first side of the generator, and a second wall
to separate the interior of the cavity from a second side of the
generator. The first wall and the second wall define the axial ends
of the cavity, and the duct extends through the interior of the
cavity from an opening in the first wall of the cavity to an
opening in the second wall of the cavity.
[0036] The ends of the cavity are closed by a wall each. The walls
separate the cavity form the first side and from the second side of
the generator. The walls define the axial end of the cavity. The
first side and the second side of the generator are axial sides of
the generator.
[0037] The first end of the cavity is closed by a wall. The wall
comprises an opening. A first end of the duct is connected to the
opening in the wall of the first end of the cavity.
[0038] The second end of the cavity comprises a wall. The wall
comprises an opening and the second end of the duct is connected to
the opening in the wall of the second end of the cavity.
[0039] Thus, the duct connects the first side of the generator with
the second side of the generator in a way that air can flow through
the duct from the first side of the generator to the second side of
the generator. The air within the duct is separated from the air in
the cavity and will not mix with the air in the cavity.
[0040] Thus the warm air that carries the heat of the generator can
be transported through the cavity separated from the cool air in
the cavity.
[0041] Thus the connection to an air inlet into the cavity and the
connection to allow air to exit the generator are arranged at the
same side of the generator. Thus the connection is easier to
establish and easier to reach by personnel for service purpose.
[0042] In addition, one side of the generator is free of
connections of the cooling system. Thus the side free of connection
scan be closed by a cover of a housing. Thus one side of the
generator protected to prevent, that wind, aerosols and water can
enter the generator.
[0043] Wind, aerosols, and water can cause damage in the generator
due to abrasion and corrosion. Thus one side of the generator is
protected against damage.
[0044] The stator of the generator is connected to a stationary
part of the wind turbine. The stator is arranged with a certain
radial distance to the stationary part. The stator is connected to
the stationary part by a wall on each axial side of the stator. The
stator, the stationary part, and the walls define a cavity. This
cavity is used as the cavity for the cooling system, to move air
through the cavity.
[0045] The stator comprises a plurality of ducts that connect the
cavity with the air gap in a way that the air from the cavity flows
into the air gap, and along the air gap to the first side and to
the second side of the generator.
[0046] The stator comprises a plurality of ducts that connect the
cavity with the air gap in a way that the air present in the cavity
can flow through the plurality of ducts into the air gap of the
generator.
[0047] Thus, the air is moved by the fan into the cavity and
through the plurality of ducts into the air gap of the electrical
generator. The air flows along the air gap of the electrical
generator and cools the stator and the rotor of the generator.
[0048] The plurality of ducts in the stator of the generator are
openings leading through the lamination package of the stator.
These openings can be gaps between stacks of lamination plates of
the stator.
[0049] The excess heat is present in the air gap and in the parts
of the rotor and stator adjacent to the air gap.
[0050] Thus, the cool air from the cavity flows along the air gap
and cools the stator and the rotor of the electrical generator.
Thus, excess heat is removed from the generator during the
operation of the wind turbine.
[0051] The cool air from the cavity flows through a plurality of
ducts into the air gap.
[0052] Thus, the cooling air enters the air gap in different
places. Thus, the cooling air is equally distributed in the air
gap. Thus, the cooling effect within the air gap is quite
equalized.
[0053] The cool air from the cavity is equally distributed in the
air gap and thus, the cooling effect along the surface of the rotor
and the stator is equalized. Thus, no hot spots along the surface
of the rotor and the stator in the generator can develop.
[0054] Thus, the cooling of the generator is optimized.
[0055] The air flows along the air gap in both directions to exit
the air gap at the first side and the second side of the generator.
The first side and the second side are axial ends of the
generator.
[0056] Thus, the warm air carries the excess heat out of the
generator into both axial directions towards the sides of the
generator. Thus, the way of the air moving through the air gap is
minimized. Thus, the cooling effect of the cooling system is
optimized.
[0057] The air exiting the air gap at the first side of the
generator flows through the duct from the first side to the second
side of the generator. There the air from the first side meets the
air that exits the air gap at the second side of the generator.
[0058] Thus, the duct allows the air to flow back from the first
side to the second side so that the air flows following the two
directions of the air gap can be combined and can exit the wind
turbine together through one exit.
[0059] Thus, only one exit from the wind turbine for the warm air
has to be provided.
[0060] The exit used by the warm air to flow out of the wind
turbine is problematic in the sense of rain and humidity can enter
the wind turbine through the exit when the wind turbine is not in
operation. Rain water and humidity are problematic for mechanical
and electrical components in the wind turbine. Due to the
arrangement described, one exit out of the wind turbine can be
avoided.
[0061] Thus, one opening in the wind turbine can be avoided. Thus,
one possibility for rain and humidity to enter the wind turbine is
avoided. Thus, problems for the mechanical and electrical
components in the wind turbine due to humidity and rain water are
minimized.
[0062] The air flows along the air gap in two axial directions. The
air exits the air gap at two axial ends of the generator. At the
axial ends of the generator stator, the air flows through the
winding overhang of the windings of the stator. The winding
overhangs produce excess heat during operation and need to be
cooled.
[0063] Thus the air from the air gap cools the winding overhang of
the stator windings.
[0064] The rotor is arranged radially outward of the stator and the
stator is attached to a main shaft of the wind turbine and the
cavity is arranged between the stator and the main shaft.
[0065] The rotor of the generator is arranged rotatable in respect
to the stator outside of the stator. Thus the generator comprises
an outer rotor.
[0066] The stator of the electrical generator is connected to a
main shaft. The main shaft is connected to the nacelle of the wind
turbine. The stator is arranged radially outward of the main shaft.
The stator is connected to the main shaft by two walls, one at each
axial end of the stator.
[0067] A cavity is defined between the stator and the main shaft
and the two walls that support the stator in respect to the main
shaft.
[0068] This hollow space between the stator and the main shaft is
used as a cavity for the described cooling system. Thus, the space
between the stator and the main shaft is a part of the cooling
system so that air can move through the cavity to cool the
generator.
[0069] Thus a hollow space already present in the wind turbine is
used as a cavity for the cooling system at the stator. Thus, no
additional space is needed for the cavity.
[0070] In addition no additional installation is needed to form a
cavity within the generator of the wind turbine. Thus, material and
space within the wind turbine is saved.
[0071] The wind turbine comprises a nacelle, and the electrical
generator is attached to the nacelle. The nacelle comprises a
housing. An air outlet connects the interior of the generator to
the exterior of the wind turbine. The air outlet is arranged
between the nacelle and the rotor of the generator to allow the
warm air from inside the generator to exit the wind turbine.
[0072] The electrical generator of the wind turbine is attached to
the nacelle. The stator of the electrical generator is connected to
the stationary part of the wind turbine in the nacelle. The rotor
of the electrical generator is connected rotatable in respect to
the stator of the generator.
[0073] The rotor is rotatable in respect to the stationary part of
the wind turbine and thus in respect to the housing of the nacelle.
A gap is present between the rotor of the generator and the housing
of the nacelle to allow the rotation of the rotor.
[0074] The air outlet is arranged within the gap between the
nacelle and the rotor of the generator. The warm air from inside
the generator exits the wind turbine through the gap between the
generator rotor and the housing of the nacelle.
[0075] Thus an opening already present in the wind turbine is used
to allow the warm air to exit the wind turbine. Thus no additional
opening has to be provided. Openings in the housing of the wind
turbine are potential entry ports for humidity, rain and
particles.
[0076] Thus an additional entry port for humidity, rain, and
particles can be avoided and the entry of humidity, rain, and
particles is limited.
[0077] The air outlet comprises a sealing.
[0078] The gap between the nacelle and the rotor of the generator
is protected by a sealing. This sealing can be a labyrinth sealing
for example.
[0079] The sealing prevents the entry of humid air and rain into
the wind turbine. The area of the gap and the sealing is used to
allow the warm air from the generator to exit the wind turbine.
[0080] Thus, the entry of humid air and rain from outside of the
wind turbine is prevented, while the warm air can exit the wind
turbine.
[0081] Humid air and rain can cause damage due to corrosion in the
wind turbine. Humid air and rain is hindered in entering the wind
turbine. Thus damage is prevented.
[0082] An air inlet duct is connected to a fan, and a filter is
attached to the air inlet duct so that the air is filtered before
it is blown into the cavity.
[0083] The air is blown by the fan through the air inlet into the
cavity. The fan is connected to an air inlet duct and the air inlet
duct comprises a filter.
[0084] Thus, the air is filtered before it enters the cavity. Thus,
the air within the cavity is filtered. Thus, the air flowing
through the plurality of ducts into the air gap is filtered.
[0085] Thus, no foreign particles flow with the air into the cavity
and through the plurality of ducts into the air gap of the
generator. Thus, damages caused by foreign particles in the air gap
of the generator are avoided.
[0086] The filter is an aerosol filter.
[0087] Aerosols are particles like pollen, or salt, or dust, or
sand for example. Aerosols can cause damage in the generator of the
wind turbine due to corrosion and abrasion.
[0088] The aerosols are filtered from the air before it enters into
the cavity and from there into the air gap of the generator. Thus,
damages occurring from aerosols particles like pollen, salt, dust,
moisture or sand in the air gap of the generator are avoided.
[0089] The nacelle comprises an air inlet for air to enter the
nacelle.
[0090] The fan moves air from the nacelle into the cavity. Thus air
will flow from outside of the wind turbine into the nacelle. Thus,
an air inlet needs to be provided to allow air to enter the
nacelle.
[0091] Thus, controlled entry of air into the nacelle is provided.
Thus, the uncontrolled entry of air through gaps in the housing of
the nacelle is minimized.
[0092] The air inlet to the nacelle comprises a dehumidifier and/or
a filter for aerosols.
[0093] Aerosols are particles like salt, or sand, or dust, or
pollen for example.
[0094] Aerosols cause damage in the electrical generator of the
wind turbine, by corrosion or abrasion.
[0095] The air inlet comprises a filter to filter out the
aerosols.
[0096] Thus, the amount of salt, sand, dust, moisture or pollen
that enters the nacelle together with the air is reduced. Thus,
also the amount of salt, sand, moisture or pollen that enters the
cavity and the air gap of the generator is reduced.
[0097] Thus, damages caused by salt, sand, dust, moisture or pollen
in the air gap of the generator are reduced.
[0098] The dehumidifier removes water from the air. This includes
water in the gaseous phase, like humidity, and water in the liquid
phase, like mist, fog, or droplets. A dehumidifier removing mist,
fog, or droplets of water from the air is also called a
demister.
[0099] Humidity and water cause problems and damages in the wind
turbine due to corrosion and cause insulation problems. The air
entering the nacelle flows through the dehumidifier, and the
moisture or humidity in the air is reduced. Thus the level of
humidity of the air in the nacelle is reduced.
[0100] In addition the level of humidity of the air that is moved
by the fan into the cavity and then through the air gap is
reduced.
[0101] Thus the probability of damages due to humidity and water in
the nacelle and the generator is reduced. Thus the lifetime of the
generator is increased.
[0102] The air inlet of the nacelle is arranged in the back wall of
the housing of the nacelle.
[0103] The nacelle of the wind turbine shows a front end and a back
end. The rotor of the wind turbine is arranged at the front end of
the nacelle. The back end of the nacelle is the end of the nacelle
pointing away from the front end of the nacelle.
[0104] During the operation of the wind turbine the wind advances
towards the nacelle of the wind turbine. It flows through the rotor
of the wind turbine and then along the nacelle.
[0105] Thus the back wall of the nacelle does not experience direct
wind pressure during the operation of the wind turbine.
[0106] Thus, no air is pushed through the air inlet into the
nacelle of the wind turbine by the wind pressure. The air needed
for cooling for the generator is sucked through the air inlet at
the back of the nacelle by the fan.
[0107] The air inlet of the nacelle is arranged at a side of the
housing of the nacelle.
[0108] The air advancing towards the wind turbine flows through the
rotor of the wind turbine and then along the sides of the
nacelle.
[0109] Thus, the sides of the nacelle do not experience wind
pressing against the housing during the operation of the wind
turbine. Thus, no air is pushed by the wind into the nacelle of the
wind turbine.
[0110] The air needed for cooling of the generator is sucked
through the air inlet at a side of the nacelle. In addition, the
side of the nacelle comprises a large area that is not used
otherwise.
[0111] Thus, the air inlet is arranged at a side of the nacelle
without occupying space needed for other installations and
components of the wind turbine.
[0112] The plurality of ducts in the stator is arranged in the
lamination plates of the generator.
[0113] Thus, the air for cooling the generator flows through the
lamination plates of the generator and thus cools the lamination
plates of the generator.
[0114] Thus, the cooling of the generator is enhanced.
[0115] The plurality of ducts in the stator are gaps between at
least two stacks of lamination plates of the generator.
[0116] The lamination plates in the generator are arranged in
stacks. Spacers are arranged between the stacks of lamination
plates.
[0117] Thus, gaps are present between the stacks of lamination
plates. These gaps between the stacks of lamination plates can be
used as ducts to allow the air from the cavity to flow through the
stator of the generator and thus into the air gap of the
generator.
[0118] The cooling system as described above is used for cooling a
generator of a wind turbine.
BRIEF DESCRIPTION
[0119] Some of the embodiments will be described in detail, with
reference to the following figures, wherein like designations
denote like members, wherein
[0120] FIG. 1 shows a first embodiment of a cooling system of a
wind turbine generator:
[0121] FIG. 2 shows a second embodiment of the cooling system;
[0122] FIG. 3 shows a third embodiment of the cooling system;
and
[0123] FIG. 4 shows an embodiment of an air inlet at the side of
the nacelle.
DETAILED DESCRIPTION
[0124] FIG. 1 shows a first embodiment of a cooling system of a
wind turbine generator.
[0125] The wind turbine comprises a nacelle 1 and a generator. The
generator comprises a rotor 2 and a stator 3. An air gap 17 is
present between the rotor 2 and the stator 3. The rotor 2 is
arranged around the stator 3 of the generator. Thus the rotor 2 is
arranged radially outward of the stator 2.
[0126] A cavity 4 is abutting on the stator 3. The cavity is
arranged radially inward of the stator 3 between the stator 3 and
the main shaft 10 of the wind turbine.
[0127] The cavity 4 is limited by the stator 3 of the generator at
the outer side and by the shaft 10 of the wind turbine at the inner
side. The generator comprises a first side 20 and a second side 21.
The cavity 4 is mainly closed by a wall to separate the cavity from
the first side 20 and at the second side 21 of the generator. The
wall at the first side 20 and the second side 21 is arranged mainly
radial and connects the stator 3 and the shaft 10.
[0128] A fan 14 blows air into the cavity 4. The fan 14 is
connected to an air channel 15. The air channel 15 is connected to
an air inlet 5 in the wall of the cavity 4. Thus the air flow 8
goes from the fan 14 through the air channel 15 and the air inlet 5
into the cavity 4.
[0129] The air flow 8 is leading from the cavity 4 through ducts 16
in the stator 3 into the air gap 17 between the rotor 2 and the
stator 3. The air flow 8 is going along the air gap 17 into both
directions towards the open end of the air gap 17.
[0130] The air flow 8 cools the part of the rotor 2 and the stator
3 adjacent to the air gap 17. At the end of the air gap 17 the air
flow 8 flows through the winding overhang 18 and cools the winding
overhang 18.
[0131] From the winding overhang 18 the air flow 8 is guided to an
air outlet 6.
[0132] A duct 9 is arranged within the cavity 4. A first end of the
duct 9 is connected to the wall at the first side 20 of the
generator. The second end of the duct 9 is connected to the wall at
the second side 21 of the generator in a way that air from the
first side of the generator flows through the duct 9 to the second
side 21.
[0133] Thus the air flow 8 from the first side 20 flows through the
duct 9 and is there combined with the air flow 8 on the second side
21 of the generator.
[0134] Thus the duct 9 is used to guide the air flow 8 from one
side of the generator to the other side of the generator and to the
air outlet 6.
[0135] The air outlet 6 is arranged between the rotor 2 of the
generator and the housing of the nacelle 1.
[0136] The air flow 8 exits the air gap 17 at both sides towards
the first side 20 and the second side 21 of the generator. The part
of the air flow 8 that leaves the air gap 17 at the first side 21
of the generator flows through the duct 9 towards the second side
21. The air flow 8 recombines at the second side 21 and is then
leaving the wind turbine at the air outlet 6 between the rotor 2 of
the generator and the housing of the nacelle 1.
[0137] In this first embodiment the air is taken from within the
nacelle 1. An aerosol filter 7 is connected to the fan 14 and/or
the air channel 15 to filter aerosols like dust, salt, moisture,
pollen, or sand form the air.
[0138] The air in the cavity 4 is kept under a higher pressure then
the ambient air, to force the air to flow through the ducts 16 into
the air gap 17.
[0139] FIG. 2 shows a second embodiment of the cooling system.
[0140] FIG. 2 shows a second embodiment of the cooling system. The
air used for cooling the generator is taken from outside of the
nacelle 1. The nacelle 1 comprises an air inlet 13 at the back side
12 of the nacelle 1. An air channel 15 connect the air inlet 13
with the filter 7, the fan 14, and with the air inlet 5 of the
cavity 4.
[0141] From the cavity 4 the air flow 8 goes through ducts 16
through the stator into the air gap 17, from there along the air
gap 17, to the winding overhangs 18, and to an air outlet 6 between
the rotor 2 of the generator and the housing of the nacelle 1.
[0142] An aerosol filter 7 is connected to the air inlet 13 and/or
the air channel 15 to filter dust, salt, pollen, moisture, or sand
form the air.
[0143] The air outlet 6 comprises a sealing. This sealing can be a
labyrinth-sealing for example. The air inside the cooling system is
kept at a higher pressure then the air surrounding the wind
turbine. The air flow 8 from the inside of the cooling system flows
through the sealing and exits the wind turbine.
[0144] FIG. 3 shows a third embodiment of the cooling system.
[0145] The nacelle 1 comprises an opening in the back side 12 of
the nacelle 1. The opening is used as an air inlet 13 for the
cooling system. The air inlet comprises a dehumidifier 11 that is
arranged at the opening in the back side 12 of the nacelle 1.
[0146] The air inlet 13 is connected to an air channel 15. A fan 14
is arranged in the air channel 15 to move the air from outside of
the nacelle 1 through the dehumidifier 11 and the air channel 15.
The air flow 8, generated by the fan 14, is forced through the air
inlet 5 into the cavity 4.
[0147] An additional filter, for example an aerosol filter, for
dust, salt, sand, moisture or pollen, can be connected to the air
channel 15.
[0148] The air pressure in the cavity 4 is kept on a higher level
than the pressure of the air surrounding the wind turbine.
[0149] The cavity 4 is connected by ducts 16 with the air gap 17,
so that the air in the cavity 4 flows through the duct 16 into the
air gap 17. The air gap comprises a first end that is present at
the first side 20 of the generator, and the air gap comprises a
second end that is present at the second side 21 of the
generator.
[0150] The air flows along the air gap 17 towards both end of the
air gap 17 and collects at the first side 20 and the second side
21.
[0151] The first side 20 of the generator is connected to the
second side 21 by a duct 9 in a way that the air from the first
side 20 flows through the duct 9 towards the second side 21 of the
generator. The cavits is separated from the first side 20 and the
second side 21 of the generator by a wall on each side. The walls
connect the stator 3 and the shaft 10.
[0152] The first end of the duct 9 is connected to an opening in
the wall at the first side 20 of the generator. The second end of
the duct 9 is connected to an opening in the wall at the second
side 21 of the generator. The duct 9 is arranged between the
opening in the wall on the first side 20 and the opening in the
wall on the second side 21 so that the duct leads through the
cavity 4.
[0153] The air flow 8 from the air gap 17 collects at the second
side 21 of the generator. An air outlet 6 is arranged between the
housing of the nacelle 1 and the rotor 2 of the generator. The air
flow exits the wind turbine at the air outlet 6.
[0154] FIG. 4 shows an air inlet at the side of the nacelle.
[0155] FIG. 4 shows a cut through the nacelle 1 of a wind turbine.
FIG. 4 shows a view from the back side of the nacelle 1 into the
nacelle 1 towards the generator of the wind turbine.
[0156] The nacelle 1 comprises a side wall 19. An air inlet is
arranged in the side wall 19 of the nacelle 1. A dehumidifier 11 is
arranged at the air inlet. An air channel 15 leads along the inner
side of the housing of the nacelle 1. The air cannel 15 comprises a
fan 14 that forces the air through the air inlet 5 into the cavity
in the generator of the wind turbine.
[0157] The illustration in the drawings is in schematic form. It is
noted that in different figures, similar or identical elements are
provided with the same reference signs.
[0158] Although the present invention has been described in detail
with reference to the preferred embodiment, it is to be understood
that the present invention is not limited by the disclosed
examples, and that numerous additional modifications and variations
could be made thereto by a person skilled in the art without
departing from the scope of the invention.
[0159] It should be noted that the use of "a" or "an" throughout
this application does not exclude a plurality, and "comprising"
does not exclude other steps or elements. Also elements described
in association with different embodiments may be combined. It
should also be noted that reference signs in the claims should not
be construed as limiting the scope of the claims.
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