NZ627914B - Hydraulic turbine - Google Patents
Hydraulic turbineInfo
- Publication number
- NZ627914B NZ627914B NZ627914A NZ62791414A NZ627914B NZ 627914 B NZ627914 B NZ 627914B NZ 627914 A NZ627914 A NZ 627914A NZ 62791414 A NZ62791414 A NZ 62791414A NZ 627914 B NZ627914 B NZ 627914B
- Authority
- NZ
- New Zealand
- Prior art keywords
- runner
- coating layer
- hydraulic turbine
- water
- pressure chamber
- Prior art date
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 251
- 239000011247 coating layer Substances 0.000 claims abstract description 140
- 239000003973 paint Substances 0.000 claims abstract description 59
- 239000011248 coating agent Substances 0.000 claims description 39
- 238000000576 coating method Methods 0.000 claims description 39
- 238000011144 upstream manufacturing Methods 0.000 claims description 14
- 150000002500 ions Chemical class 0.000 claims description 12
- 239000010410 layer Substances 0.000 description 30
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 20
- 239000005871 repellent Substances 0.000 description 13
- 238000000926 separation method Methods 0.000 description 12
- 229910052742 iron Inorganic materials 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 210000003128 Head Anatomy 0.000 description 5
- 238000010248 power generation Methods 0.000 description 5
- 230000001629 suppression Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminum Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000000875 corresponding Effects 0.000 description 3
- 230000002940 repellent Effects 0.000 description 3
- 229910001593 boehmite Inorganic materials 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006011 modification reaction Methods 0.000 description 2
- 230000002035 prolonged Effects 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 210000003027 Ear, Inner Anatomy 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Abstract
hydraulic turbine 1 comprises a turbine body 2 having a runner configured to be rotated by water flowing therein during hydraulic turbine operation, and a guide vane 5 configured to adjust a flow rate of the water flowing into the runner 8. A running water surface is provided in the turbine body, with the running water surface defining a channel for water, and a coating layer provided on the running water surface. The coating layer is formed by hydrophilic paint. with the running water surface defining a channel for water, and a coating layer provided on the running water surface. The coating layer is formed by hydrophilic paint.
Description
HYDRAULIC TURBINE
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of
priority from Japanese Patent Application Nos. 70681,
35828 and 2014-137072, filed on August 20, 2013,
February 26, 2014 and July 2, 2014, respectively, the entire
contents of which are incorporated herein by reference.
FIELD
The Embodiments relates to a hydraulic turbine. A pipe is
also disclosed.
BACKGROUND
In general, hydraulic turbines such as a Francis turbine, a
Kaplan turbine or a Bulb e serving as an axial flow turbine
or the like are known. Further, as a hydraulic turbine capable
of conducting both power generation and pumped storage, a
Francis pump hydraulic turbine is known. Here, the s
pump hydraulic turbine (hereinafter simply referred to as
Francis turbine) will be described by way of example.
[0004]
In the Francis turbine, water flows from an upper
reservoir into a spiral , and the water flowing into the
casing flows into a runner through stay vanes and guide vanes.
The guide vanes are configured to be rotated to change an
opening degree, thereby enabling ment of a flow rate of
the water g into the runner. The runner is rotated around
a hydraulic turbine rotating axis by the water flowing thereinto.
Thereby, power is generated at a generator connected to the
runner via a main shaft. The water flowing out of the runner is
discharged to a lower reservoir through a draft tube.
In this way, the water from the upper reservoir is
discharged to the lower reservoir through the casing, the stay
vanes, the guide vanes, the , and the draft tube. In the
meantime, the water flows along a running water surface of a
channel which is defined by the running water surface of, for
instance, the casing. Thereby, a friction loss occurs at a flow of
the water along the running water surface. The friction loss is
different depending on a flow velocity and a Reynolds number.
In general, the higher the flow velocity, the greater the on
loss, whereas the smaller the Reynolds number, the greater the
friction loss.
In the Francis turbine, various losses in addition to the
friction loss can occur. For example, a secondary flow loss
caused by ion of a flow that does not follow a main flow,
a separation loss caused by generation of separation from a flow,
and a vortex loss caused by a swirl flow generated from a
runner outlet in a draft tube are exemplified.
[0007]
The secondary flow loss and the separation loss or the
like can be reduced by optimizing a shape of each part.
r, even in the case of optimizing the shape of each part,
the friction loss occurs at a flow of water along a running water
surface of each part. For this reason, there is a limitation in
reducing the losses of the Francis turbine as a whole by
reducing the secondary flow loss and the separation loss or the
like.
[0007a]
It is an object of the invention to at least provide the public
with a useful choice.
In one aspect of the invention there is provided a hydraulic
turbine comprising:
a turbine body having a runner ured to be rotated
[Followed by page 2a]
by water flowing therein during hydraulic turbine operation, and
a guide vane configured to adjust a flow rate of the water
flowing into the ;
a running water surface provided in the turbine body, the
g water e defining a channel for water; and
a coating layer provided on the running water surface,
the coating layer being formed by hydrophilic paint.
[0007c]
In a further aspect of the invention there is provided a
hydraulic turbine comprising:
a casing into which water flows;
a runner having a crown, a band, and a ity of
runner blades provided between the crown and the band, the
runner being configured to be rotated by the water flowing
therein from the casing; and
an upper cover provided outside the crown of the runner,
the upper cover being configured to form a back pressure
chamber between the crown and the upper cover,
wherein a back pressure chamber coating layer having
hydrophilicity is provided on a surface of the crown which is
located in the back pressure r.
[0007d]
In a further aspect of the invention there is provided a
lic turbine comprising:
a casing into which water flows;
a runner having a crown, a band, and a plurality of
runner blades ed between the crown and the band, the
runner being configured to be rotated by the water flowing
therein from the casing; and
a lower cover provided outside the band of the ,
the lower cover being configured to form a lateral pressure
chamber between the band and the lower cover,
wherein a lateral pressure chamber coating layer having
[Followed by page 2b]
hydrophilicity is provided on a e of the band which is
located in the l pressure chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
is a view illustrating an overall configuration of a
hydraulic turbine in a first embodiment;
is a cross-sectional view illustrating a coating
layer provided on a running water surface of the hydraulic
turbine of and is a view viewed in a direction of
[followed by page 3]
[Followed by page 3]
arrow P of ;
FIGS. 3A to 3C are views illustrating a method of forming
the g layer illustrated in FIGS. 2A and 2B;
is a view illustrating a function of dimples of the
coating layer of FIGS. 2A and 2B;
is a view illustrating a cover non-coating region
formed on an upper cover and a lower cover in a second
embodiment;
is a longitudinal section view illustrating a runner
in a third embodiment;
is a cross-sectional view taken along line A-A
which illustrates a runner blade of the runner of
is a view illustrating a modification of
is a cross-sectional view illustrating a coating layer
in a fourth embodiment;
is a cross-sectional view illustrating an overall
configuration of a hydraulic turbine in a fifth embodiment;
is a partially ed cross-sectional view of A is a cross-sectional view illustrating a coating
layer in the hydraulic turbine of , and B is a view
viewed in a direction of arrow P of A;
FIGS. 13A to 13C are views illustrating a method of
g the g layer illustrated in FIGS. 12A and 12B;
is a view illustrating a function of dimples of the
coating layer illustrated in FIGS. 12A and 12B;
is a schematic view illustrating a pipe in a sixth
embodiment; and
is a cross-sectional view rating a coating
layer provided on a running water surface of the pipe of FIG.
DETAILED PTION
Unless the context y requires otherwise, throughout
the description and the claims, the words “comprise”,
“comprising”, and the like are to be construed in an inclusive
[Followed by page 3a]
sense as opposed to an exclusive or exhaustive sense; that is to
say, in the sense of "including, but not d to".
[0009a]
A hydraulic turbine according to an embodiment includes
a turbine body, a running water surface provided in the turbine
[followed by page 4]
[Followed by page 4]
body, the running water surface defining a l for water,
and a g layer provided on the running water surface, the
coating layer being formed by water-repellent paint or
hydrophilic paint.
A hydraulic turbine according to an embodiment es
a casing into which water flows, and a runner rotated by the
water flowing therein from the casing. The runner es a
crown, a band, and a plurality of runner blades provided
between the crown and the band. An upper cover is provided
outside the crown of the runner and forms a back pressure
chamber between the crown and the upper cover. A back
pressure chamber coating layer having hydrophilicity is provided
on a surface of the crown which is d in the back re
chamber.
A hydraulic turbine according to an embodiment includes
a casing into which water flows, and a runner rotated by the
water flowing therein from the casing. The runner includes a
crown, a band, and a plurality of runner blades provided
between the crown and the band. A lower cover is provided
outside the band of the runner and forms a lateral pressure
chamber between the band and the lower cover. A lateral
pressure chamber coating layer having hydrophilicity is ed
in a surface of the band which is located in the lateral pressure
chamber.
A pipe according to an embodiment is a pipe connected
to a hydraulic turbine. The pipe includes a pipe body, a running
water surface that is provided in the pipe body and defines a
channel for water, and a coating layer that is ed on the
running water surface and has hydrophilicity.
Hereafter, a hydraulic turbine in embodiments will be
described with nce to the drawings. Here, a Francis
turbine will be described as an example of the hydraulic turbine.
(First embodiment)
First, a hydraulic turbine in a first embodiment will be
described using FIGS. 1 to 4.
As illustrated in a Francis turbine 1 is equipped
with a turbine body 2 and a running water surface 20 (see ) provided in the turbine body 2.
The turbine body 2 has a spiral casing 3 into which water
flows from an upper reservoir 201 (see ) h a
hydraulic iron pipe 200 during hydraulic turbine operation, a
plurality of stay vanes 4, a plurality of guide vanes 5, and a
runner 8. Among them, the stay vanes 4 guide the water
flowing into the casing 3 to the guide vanes 5 and the runner 8,
and are disposed at a given interval in a circumferential
direction. A channel 21 in which the water flows is formed
n the stay vanes 4. The guide vanes 5 guide the inflow
water to the runner 8, and are disposed at a given interval in a
circumferential direction. The channel 21 in which the water
flows is formed between the guide vanes 5.
Upper and lower covers 6 and 7, which are opposite to
each other, are provided at upper and lower sides of the guide
vanes 5, respectively. The upper cover 6 and the lower cover 7
bly support the guide vanes 5. The guide vanes 5 are
rotated to change an opening angle, and thereby a flow rate of
the water flowing into the runner 8 is adapted to be adjustable.
In this way, a capacity of power generation of a tor motor
3O 11 to be described below is adapted to be adjustable.
The runner 8 is configured to be rotatable around an axis
X of on with respect to the casing 3, and is rotatably
driven by the water flowing from the casing 3 during the
hydraulic turbine operation. Further, the runner 8 has a
plurality of runner blades 9 ed at a given interval in a
circumferential direction, and the channel 21 in which the water
flows is formed between the runner blades 9.
The generator motor 11 is connected to the runner 8 via
a main shaft 10. The generator motor 11 tes power
based on rotation of the runner 8 during the hydraulic turbine
operation, and is configured to rotatably drive the runner 8
during pump ion g pumped storage operation). A
draft tube 12 for restoring a pressure of the water flow flowing
out of the runner 8, as a part of the turbine body 2, is ed
at a downstream side of the runner 8 during the hydraulic
turbine operation. The draft tube 12 is connected to a lower
reservoir 202 (see ), and the water rotatably driving the
runner 8 is d to be discharged to the lower reservoir 202.
[0020]
The running water e 20 (see ) is provided
for each of the casing 3, the stay vanes 4, the guide vanes 5,
the upper cover 6, the lower cover 7, the runner 8, and the
draft tube 12 of the aforementioned e body 2. Each
running water surface 20 is adapted to define the channel 21 for
the running water such that the water flows in the channel 21.
As illustrated in , the running water surface 20 is
provided with a coating layer 30 formed by repellent paint.
The coating layer 30 can be formed on the running water
surface 20 by coating the water—repellent paint. The
water—repellent paint is not particularly limited as long as it has
water repellency. For example, paint containing fluorine resin
or silicon resin, or ship's bottom paint can be used. Further,
3O the water—repellent paint preferably has a contact angle of, for
instance, 75 degrees or more, and more preferably 90 degrees
or more, (wherein the contact angle is an angle formed between
a surface of the coating layer 30 which is a solid surface and a
tangent line to an edge of the water being in contact with the
solid surface).
The coating layer 30 is ably provided with a
plurality of (or multiple) dimples 31 that are open to the
channel 21. The dimples 31 are formed in the coating layer 30
in a concave shape like a small pit. Each dimple 31 preferably
has a depth that is not less than 0.05 times and not more than
0.15 times a diameter of an inscribed circle of the dimple 31
when a planar shape of the dimple 31 is a polygonal shape, or a
diameter of the dimple 31 when a planar shape of the dimple 31
is a circular shape. Here, as the depth of the dimple 31 is set
to not less than 0.05 times the diameter, the dimple 31 can be
formed with high ion. As the depth of the dimple 31 is
set to not more than 0.15 times the diameter, an increase in
friction loss caused by the presence itself of the dimple 31 can
be suppressed. On the other hand, the planer shape of the
dimple 31 is not particularly limited, but it is ably, for
instance, a circular shape as illustrated in or a
hexagonal shape. For example, if the diameter of the inscribed
circle of the polygonal dimple 31 or the diameter (Dd illustrated
in ) of the circular dimple 31 is 1 mm, the depth (Hd
illustrated in ) of the dimple 31 is preferably not less
than 50 pm and not more than 150 pm. A depth of the coating
layer 30 is not particularly d if the dimples 31 can be
formed, if the running water surface 20 is not exposed to the
bottoms of the dimples 31, and if the material of the coating
layer 30 can be left behind.
Further, an interval between the dimples 31 adjacent to
each other is preferably not less than 0.8 times and not more
3O than 0.12 times the er of the inscribed circle of the
dimple 31 when the planar shape of the dimple 31 is the
polygonal shape, or the diameter of the dimple 31 when the
planar shape of the dimple 31 is the circular shape. Thereby,
an effect of reducing viscosity resistance of the water flow
according to the dimples 31 can be effectively ed, which
is experimentally confirmed by the inventors. For example, if
the diameter of the inscribed circle of the polygonal dimple 31
or the er (Dd illustrated in ) of the circular dimple
31 is 1 mm, the interval (G illustrated in ) between the
dimples 31 is ably not less than 0.8 mm and not more
than 1.2 mm.
As illustrated in FIGS. 3A to 3C, the coating layer 30 can
be formed using, for example, a mold 40 having bulges 41
corresponding to the dimples 31 of the coating layer 30. In
this case, as illustrated in , the repellent paint is
applied to the g water surface 20 in a film shape at a
given ess first, and a paint film 30a is formed.
Subsequently, as illustrated in , the mold 40 is pressed
against the paint film 30a of the water—repellent paint. In this
case, the mold 40 is pressed such that the paint film 30a
remains between the bulges 41 of the mold 40 and the running
water surface 20. Next, in the state in which the mold 40 is
pressed, the paint film 30a is dried and cured. After the paint
film 30a is cured, the mold 40 is removed as illustrated in 3C. In this way, the coating layer 30 can be obtained in the
present embodiment. The method of forming the coating layer
is not limited to the aforementioned method. For example,
after the paint film of the water—repellent paint is cured, the
mold 40 may be placed on the cured paint film, and the
water—repellent paint may be applied to the surroundings of the
bulges 41 of the mold 40, and be cured. Thereby, the coating
layer 30 can also be ed in the present embodiment.
Such a coating layer 30 is provided on each of the
3O running water surfaces 20 of the casing 3, the stay vane 4, the
guide vane 5, the upper cover 6, the lower cover 7, the runner
8, and the draft tube 12. In other words, without other
restraints, the coating layer is preferably provided on the
running water surface 20 of each member of the Francis turbine
1.
Next, an ion of the t embodiment configured
in this way will be described.
When the hydraulic turbine operation is conducted in the
Francis turbine according to the present embodiment, as
illustrated in water flows from the upper reservoir 201
(see ) into the casing 3 through the hydraulic iron pipe
200. The water flowing into the casing 3 flows from the casing
3 into the runner 8 through the stay vanes 4 and the guide
vanes 5. The runner 8 is rotatably driven by the water flowing
into the runner 8. Thereby, the generator motor 11 connected
to the runner 8 via the main shaft 10 is driven to produce
electric power. The water g into the runner 8 is
discharged from the runner 8 through the draft tube 12 to the
lower reservoir 202. During which the hydraulic turbine
operation is ted, the guide vanes 5 are rotated. Thereby,
the opening degree of the guide vanes 5 is adjusted, and the
capacity of power generation of the generator motor 11 is
adjusted.
During pump operation, the generator motor 11 rotatably
drives the runner 8, thereby g up the water in the draft
tube 12. The water pumped up into the runner 8 flows into the
casing 3 h the guide vanes 5 and the stay vanes 4, and is
discharged from the casing 3 through the hydraulic iron pipe
200 to the upper reservoir 201. The guide vanes 5 and stay
vanes 4 guide the water flowing out of the runner 8 to the
casing 3. In this case, the opening degree of the guide vanes 5
is variable to have a proper pumpage depending on a pump
head.
During the hydraulic turbine operation and the pump
operation, a flow of the water along the running water surface
20 is formed inside the channel 21 defined by the running water
surface 20 of the casing 3, the running water surfaces 20 of the
stay vanes 4, the running water surfaces 20 of the guide vanes
, the running water surface 20 of the upper cover 6, the
running water surface 20 of the lower cover 7, the running
water surface 20 of the runner 8, and the running water surface
of the draft tube 12. The running water surface 20 is
provided with the g layer 30 (see ) formed by the
water—repellent paint. Thereby, the water flowing near the
g layer 30 can flow to be repelled from the coating layer
, and the viscosity resistance of the water flow near the
g layer 30 can be reduced. For this reason, the friction
loss of the main flow against the running water e 20 can
be reduced.
Further, as described above, the coating layer 30 is
provided with the a plurality of dimples 31. While entering or
leaving the dimples 31, part of the water is affected by a flow in
a water flow direction, and flows to circulate in the s 31
as rated in In this case, the water in the dimples
31 can flow to be repelled from walls of the dimples 31 formed
by the water—repellent paint, and smoothly circulate in the
s 31. For this reason, the water flow circulating in the
dimples 31 exerts the same function as a roller used in a
common conveyer or the like, still more reduces the viscosity
resistance of the flow of the water flowing above the dimples 31,
and allows the main flow to flow smoothly on the running water
surface 20.
Incidentally, in head energy Ph of the water flowing into
the Francis turbine 1, assuming that a y of the water be p,
3O a flow rate be Q, a head be H, and gravitational acceleration be
g, the head energy Ph is expressed as follows.
Ph = p x g x Q X H
Assuming the friction loss of the water occurring on the
running water surface 20 be Lf, Lf of the head energy Ph is used
as friction energy. Further, if the loss caused by the shape of
the hydraulic turbine, such as the secondary flow loss, the
separation loss, or the vortex loss described above, is defined
as Ls, energy Pt that can be used to rotate the runner 8 is as
follows.
Pt = Ph - Lf - Ls
However, as described above, as the running water
surface 20 is provided with the coating layer 30 formed by the
water-repellent paint, the viscosity resistance of the water flow
near the coating layer 30 can be reduced. For this reason, it is
le to reduce the friction loss Lf, and increase the energy
Pt that can be used to rotate the runner 8.
According to the present embodiment, the running water
surface 20 is provided with the coating layer 30 formed by the
repellent paint. Thereby, it is possible to reduce the
viscosity resistance of the water flow in the vicinity of the
g layer 30, and to reduce the friction loss of the water
flow flowing in the channel 21 defined by the running water
surfaces 20. For this reason, it is possible to make good use of
energy of the water flowing into the casing 3 to improve
efficiency of the hydraulic e.
Further, according to the t embodiment, the
coating layer 30 is provided with the a plurality of dimples 31.
Thereby, it is possible to more reduce the viscosity resistance of
the water flow in the vicinity of the coating layer 30, and to
more reduce the friction loss of the water flow.
3O (Second embodiment)
Next, a lic e in a second embodiment will be
described using
In the second embodiment illustrated in a main
difference is that a non—coating region is provided for an upper
cover and a lower cover, and other configurations are
imately identical to those of the first embodiment
illustrated in FIGS. 1 to 4. In the same parts as in the
first embodiment rated in FIGS. 1 to 4 are given the same
symbols, and detailed description thereof will be omitted.
As illustrated in a running water surface 20 of an
upper cover 6 has a coating region 50 in which a coating layer
is provided, and a cover non—coating region 51 in which no
coating layer 30 is provided. In the cover non—coating region
51 of these regions, the running water surface 20 of the upper
cover 6 is exposed. When viewed in a direction taken along a
onal axis Y (see of a guide vane 5 (in the state of
, the cover non—coating region 51 is formed to include
(or cover) a rotation region of the guide vane 5. In the present
ment, the cover non—coating region 51 is formed around
the rotational axis of the guide vane 5 in a circular shape.
Preferably, a radius of the cover non-coating region 51 is
approximately equal to the maximum rotation radius of the
guide vane 5 or is greater than the maximum rotation radius.
In this way, when viewed in the ion taken along the
rotational axis, the rotation region of the guide vane 5 is
adapted to avoid overlapping the coating region 50.
Like the upper cover 6, the lower cover 7 also has a
coating region 50 and a cover non-coating region 51. When
viewed in the direction taken along the rotational axis of the
guide vane 5, the cover non—coating region 51 is formed to
include the rotation region of the guide vane 5.
3O Thus, according to the present embodiment, the cover
ating region 51 of the upper cover 6 and the cover
non—coating region 51 of the lower cover 7 are formed to
include the rotation region of the guide vane 5 when viewed in
the direction taken along the rotational axis of the guide vane 5.
Thereby, it is possible to prevent the rotating guide vane 5 from
coming into contact with the coating layer 30, and to thus
prevent the coating layer 30 from being separated. Further, in
the cover non—coating region 51, since the coating layer 30 does
not intervene between the guide vane 5 and the upper cover 6
and between the guide vane 5 and the lower cover 7, a gap
between the guide vane 5 and the upper cover 6 and a gap
between the guide vane 5 and the lower cover 7 can be
ted from being reduced. Thereby, it is possible to
prevent sand or foreign substances such as dust from being put
in these gaps, and to thus t the coating layer 30 from
being scratched or separated. For this reason, the coating
layer 30 is prevented from being damaged, and the coating
layer 30 is prolonged in service life, so that it is possible to
enjoy an effect of reducing the friction loss based on the coating
layer 30 for a long time.
[0041]
(Third ment)
Next, a hydraulic turbine in a third embodiment will be
described using FIGS. 6 and 7.
In the third embodiment illustrated in FIGS. 6 and 7, a
main difference is that a non—coating region is provided for each
runner blade of a runner, and other urations are
imately identical to those of the first ment
illustrated in FIGS. 1 to 4. In FIGS. 6 and 7, the same parts as
in the first embodiment illustrated in FIGS. 1 to 4 are given the
same symbols, and detailed description thereof will be omitted.
As illustrated in FIGS. 6 and 7, a running water surface
of each runner blade 9 of a runner 8 has a pressure surface
(driving face) 9a and a suction surface 9b. r, the running
water surface 20 of the runner blade 9 has a coating region 50
for which a coating layer 30 is provided, and an upstream
non-coating region 52 in which the coating layer 30 is not
provided. The am non-coating region 52 is formed at an
upstream end (an inlet-side end or a guide vane—side end) of
each of the pressure and suction surfaces 9a and 9b of the
runner blade 9 during hydraulic turbine operation.
The upstream non-coating region 52 has a length that
follows a main flow direction and is indicated in by Li,
and is formed to extend from a crown 8a toward a band 8b.
When an outlet diameter (a diameter of a draft ide end)
of the runner 8 during the hydraulic turbine operation is defined
as De, the length Li of the upstream non—coating region 52 in
the main flow direction is preferably given as follows.
Li/De s 0.8
The length Li defined in the expression above becomes a
region in which flow separation 55 may generally occur during
the hydraulic turbine operation. This prevents the coating layer
from being provided in the region in which the flow
separation 55 may occur.
In other words, when a water flow direction of the water
g into the runner 8 during the hydraulic turbine operation
is not matched with the runner blade 9, flow separation 55 can
occur at the pressure e 9a or the n surface 9b at an
upstream end of the runner blade 9 as illustrated in
However, as described above, the am non—coating region
52 is formed on the pressure surface 9a and the suction surface
9b at the upstream end of the runner blade 9. This can
prevent the coating layer 30 from being provided in the region
in which the flow tion 55 can occur during the hydraulic
turbine operation.
Further, as illustrated in FIGS. 6 and 7, the running water
3O surface 20 of the runner blade 9 further includes a downstream
ating region 53 in which the coating layer 30 is not
provided. The downstream non—coating region 53 is formed at
a downstream end (an outlet-side end or a draft tube-side end)
of the suction surface 9b of the runner blade 9 during the
lic turbine operation.
The downstream ating region 53 has a length that
follows the main flow direction and is indicated in by Lo,
and is formed to extend from the crown 8a toward the band 8b.
When the outlet diameter (the diameter of the draft tube—side
end) of the runner 8 during the hydraulic turbine operation is
d as De, the length Lo of the downstream non—coating
region 53 in the main flow direction is preferably given as
follows.
Lo/De s 0.8
The length Lo d in the expression above becomes a
region in which cavitation 56 can generally occur during the
hydraulic turbine operation. This prevents the coating layer 30
from being provided in the region in which the cavitation 56 can
occun
In other words, when a flow rate of the water flowing into
the runner 8 is more than a design point (or when output is
high), the cavitation 56 can occur in the ty of the suction
surface 9b at a downstream end of the runner blade 9 as
illustrated in However, as described above, downstream
non—coating region 53 is formed on the suction surface 9b at the
downstream end of the runner blade 9. This can prevent the
coating layer 30 from being provided in the region in which the
tion 56 can occur during the hydraulic turbine ion.
Thus, according to the present embodiment, the
upstream non—coating region 52 is formed at the upstream end
of each of the pressure and suction surfaces 9a and 9b of the
3O runner blade 9 during the hydraulic turbine operation. This can
prevent the g layer 30 from being provided in the region
in which the flow separation 55 can occur. Further, the
downstream non-coating region 53 is formed at the downstream
end of the suction surface 9b of the runner blade 9 during the
hydraulic turbine operation. This can prevent the coating layer
from being provided in the region in which the cavitation 56
can occur. For this reason, the coating layer 30 is prevented
from being damaged by the flow separation 55 and/or the
cavitation 56, and the coating layer 30 is prolonged in service
life, so that it is le to enjoy the effect of reducing the
friction loss based on the coating layer 30 for a long time.
In the aforementioned present embodiment, as illustrated
in the downstream non—coating region 53 may be
formed also at a downstream end (an outlet-side end or a draft
tube—side end) of the re surface 9a of the runner blade 9.
In other words, the downstream non—coating region 53 may be
formed on both the pressure surface 9a and the suction surface
9b at the downstream end of the runner blade 9 during the
hydraulic turbine operation.
[0051]
Since the water flows from the draft tube 12 toward the
casing 3 during the pump operation in a direction opposite to
that during the hydraulic e operation, when the water flow
direction of the water flowing into the runner 8 is not matched
with the shape of the runner blade 9, the flow separation 55 can
occur on the pressure surface 9a or the suction surface 9b at
the draft tube—side end (the side end during the pump
operation or the downstream end during the hydraulic turbine
operation) of the runner blade 9. However, as described above,
when the ream non-coating region 53 is formed at the
draft ide ends of the pressure and suction surfaces 9a and
9b of the runner blade 9 during the hydraulic turbine operation,
it is possible to prevent the coating layer 30 from being
provided in the region in which the flow separation 55 may occur.
3O Thereby, even in the case of conducting the pump operation of
the Francis turbine 1, it is possible to prevent the coating layer
from being damaged. In other words, when the pump
ion of the Francis turbine 1 is led, the downstream
non—coating region 53 is preferably formed on both the pressure
surface 9a and the suction surface 9b at the downstream end of
the runner blade 9 during the hydraulic e operation.
(Fourth embodiment)
Next, a hydraulic turbine in a fourth embodiment will be
described using
In the fourth embodiment illustrated in a main
difference is that a coating layer is formed by hydrophilic paint,
and other configurations are approximately identical to those of
the first embodiment illustrated in FIGS. 1 to 4. In the
same parts as in the first embodiment illustrated in FIGS. 1 to 4
are given the same symbols, and detailed description thereof
will be omitted.
As illustrated in a running water surface 20 is
provided with a coating layer 60 formed by hydrophilic paint.
The coating layer 60 can be formed on the running water
surface 20 by coating the hydrophilic paint. The hilic
paint is not particularly limited as long as it has hydrophilicity.
For example, paint containing a material having a hydrophilic
group (-OH) may be properly used. Further, a t angle of
the hydrophilic paint is preferably equal to or less than, for
instance, 40 degrees.
Similarly to the coating layer 30 and the dimples 31
illustrated in FIGS. 2A and 28, the g layer 60 is ably
provided with a plurality of (or multiple) s 61 open to the
channel 21. Each dimple 61 preferably has a depth that is not
less than 0.05 times and not more than 0.15 times a diameter
of an inscribed circle of the dimple 61 when a planar shape of
3O the dimple 61 is a nal shape, or a diameter of the dimple
61 when a planar shape of the dimple 61 is a ar shape.
On the other hand, the planar shape of the dimple 61 is not
particularly limited, but it is preferably a circular shape or a
hexagonal shape. For example, if a diameter of an inscribed
circle of the polygonal dimple 61 or a diameter (for example, Dd
illustrated in of the circular dimple 61 is 1 mm, the
depth (for example, Hd illustrated in of the dimple 61 is
preferably not less than 50 pm and not more than 150 pm.
Further, an interval n the dimples 61 adjacent to
each other is preferably not less than 0.8 times and not more
than 0.12 times the diameter of the inscribed circle of the
dimple 61 when the planar shape of the dimple 61 is the
polygonal shape, or the diameter of the dimple 61 when the
planar shape of the dimple 61 is the ar shape. Thereby,
an effect of reducing viscosity resistance of the water flow
according to the s 61 can be effectively produced, which
is experimentally confirmed by the inventors. For example, if
the diameter of the inscribed circle of the polygonal dimple 61
or the diameter (Dd illustrated in of the circular dimple
61 is 1 mm, the interval (G illustrated in between the
dimples 61 is preferably not less than 0.8 mm and not more
than 1.2 mm.
Further, the coating layer 60 illustrated in can be
formed to be r to the coating layer 30 rated in , and is preferably formed on the running water surface 20
provided for each member, such as the casing 3.
During the hydraulic turbine operation and the pump
ion, a flow of the water along the running water surface
is formed inside the channel 21 defined by the g water
surface 20 of the casing 3 etc. The g water surface 20 is
provided with the coating layer 60 formed by the hydrophilic
paint. Thereby, a thin water adhesion layer 62 is formed on a
3O surface 60a of the coating layer 60 in such a manner that water
is adhered. The water adhesion layer 62 is interposed between
the main flow and the coating layer 60. Further, the water
forming the water adhesion layer 62 is not at a standstill with
respect to the coating layer 60, but it has an extremely low flow
velocity. With the above configuration, it is possible to reduce
the viscosity resistance of the water flow in the proximity of the
coating layer 60 and to reduce the friction loss of the main flow
against the running water surface 20.
Further, the coating layer 60 is provided with the a
plurality of dimples 61. In this case, the water in the dimples
61 is adapted to be adhered to walls of the dimples 61 formed
by the hydrophilic paint, and thus a flow velocity of the water in
the dimples 61 is extremely reduced. Thereby, an effect of
increasing a thickness of the water adhesion layer 62 described
above is obtained in a region in which the dimples 61 are
provided within the running water surface 20. For this reason,
the viscosity resistance of the water flow flowing above the
dimples 61 can be more reduced, and the main flow can
smoothly flow on the running water surface 20.
[0060]
Thus, according to the t embodiment, the running
water surface 20 is ed with the g layer 60 formed
by the hilic paint. Thereby, it is possible to form the
adhesion layer 62 of the water having an ely low flow
ty on the surface 60a of the coating layer 60, and to
reduce the friction loss of the water flow flowing in the l
21 defined by the running water surface 20. For this reason, it
is possible to improve the efficiency of the hydraulic turbine by
making good use of energy of the water flowing into the casing
3.
Further, according to the present embodiment, the
coating layer 60 is provided with the a plurality of dimples 61.
Thereby, it is possible to more reduce the viscosity resistance of
3O the water flow in the proximity of the coating layer 60, and to
more reduce the friction loss of the water flow.
(Fifth embodiment)
Next, a hydraulic turbine in a fifth embodiment will be
described using FIGS. 10 to 14.
In the fifth embodiment illustrated in FIGS. 10 to 14, a
main difference is that a back pressure chamber coating layer
having hydrophilicity is provided on a surface of a crown which
is located in a back pressure chamber, and a l pressure
chamber coating layer having hydrophilicity is provided on a
surface of a band which is located in a lateral pressure chamber,
and other configurations are approximately identical to those of
the first embodiment illustrated in FIGS. 1 to 4. In FIGS. 10 to
14, the same parts as in the first embodiment illustrated in
FIGS. 1 to 4 are given the same symbols, and detailed
description thereof will be omitted.
Here, as an e of the hydraulic turbine, a Francis
turbine will be described by way of example.
As rated in , a Francis turbine 101 is
equipped with a spiral casing 103 into which water flows from
an upper reservoir 201 (see ) through a hydraulic iron
pipe 200, a plurality of stay vanes 104, a ity of guide
vanes 105, and a runner 106. Among them, the stay vanes
104 are to guide the water flowing into the casing 103 to the
guide vanes 105 and the runner 106, and are disposed at a
given interval in a circumferential direction.
[0066]
The guide vanes 105 are to guide the inflow water to the
runner 106, and are disposed at a given interval in a
circumferential direction. Further, each guide vane 105 is
rotatably provided, and is configured to allow a flow rate of the
3O water flowing into the runner 106 to be adjusted by rotation and
the resultant ion in opening . Thereby, a capacity
of power generation of a generator 111 to be described below
can be adjusted.
The runner 106 is configured to be ble around a
rotational axis X relative to the casing 103, and is rotatably
driven by the water flowing therein from the casing 103.
Further, as illustrated in , the runner 106 has a crown
107, a band 108, and a ity of runner blades 109 provided
between the crown 107 and the band 108. Among them, the
runner blades 109 are disposed at a given interval in a
circumferential ion.
As illustrated in , the generator 111 is connected
to the runner 106 via a main shaft 110. The generator 111 is
configured to generate power by rotation of the runner 106. A
draft tube 112 for restoring a pressure of the water flow flowing
out of the runner 106 is provided at a downstream side of the
runner 106. The draft tube 112 is connected to a lower
reservoir 202. The water rotatably g the runner 106 is
adapted to be rged to the lower reservoir 202.
As illustrated in , a back pressure chamber 113 is
formed outside (an upper side in ) the crown 107 of the
runner 106. To be more specific, an upper cover 114 is
provided outside the crown 107, and the aforementioned back
re chamber 113 is formed between the crown 107 and
the upper cover 114. On the other hand, a lateral pressure
chamber 115 is formed outside (a right side in or a
radial outer side) the band 108 of the runner 106. More
particularly, a lower cover 116 is provided outside the band 108,
and the aforementioned lateral pressure chamber 115 is formed
between the band 108 and the lower cover 116.
Part of the water flowing through the guide vanes 105
3O flows into the back pressure and lateral pressure chambers 113
and 115 as a e flow. In other words, a back pressure
chamber-side gap portion 117 is provided at a radial outer side
(upstream side) of the crown 107. Water flows into the back
pressure chamber 113 through the back pressure chamber—side
gap portion 117. When a h-hole 118 is provided in the
crown 107 of the runner 106 as illustrated in , the
running water in the back pressure chamber 113 flows into the
draft tube 112 through the h—hole 118. Further, a back
pressure chamber-side seal portion (intermediate seal portion)
119 is provided at a radial inner side of the back pressure
chamber 113 (more ularly, between the back pressure
chamber 113 and the through-hole 118). The back pressure
chamber-side seal portion 119 is formed such that it is difficult
for water to flow due to a narrowest gap between the crown 107
that is a rotation—side portion and the upper cover 114 that is a
standstill-side. Thereby, an inflow rate of the water from guide
vanes 105 toward the back pressure chamber 113 is suppressed.
The back pressure chamber—side seal portion 119 can be formed
by a labyrinth seal.
On the other hand, a lateral re chamber—side gap
portion 120 is provided at a radial outer side eam side) of
the band 108. Water flows into the lateral pressure r
115 through the lateral pressure chamber-side gap portion 120.
The running water in the lateral pressure chamber 115 flows
into the draft tube 112 h a downstream gap portion 121
provided at a radial inner side (downstream side) of the band
108. Further, a lateral pressure chamber—side seal portion 122
is provided at a radial inner side of the lateral pressure chamber
115 (more particularly, between the lateral re chamber
115 and the ream gap portion 121). The lateral
pressure chamber—side seal portion 122 is formed such that it is
difficult for water to flow due to a narrowest gap between the
band 108 that is a rotation—side portion and the lower cover 116
that is a standstill-side. Thereby, an inflow rate of the water
from guide vanes 105 toward the lateral pressure chamber 115
is suppressed. The lateral pressure chamber-side seal portion
122 can be formed by a nth seal.
As bed above, since the back pressure chamber 113
and the lateral pressure chamber 115 form a relatively narrow
channel, a disk friction loss can occur while the water flows into
the back pressure chanwber 113 and the lateral pressure
chamber 115 and the runner 106 is rotated.
GeneraHy,sfince the channeksin the back pressure and
lateral pressure chambers 113 and 115 are relatively ,
velocity gradients of the water flows passing through the back
pressure and lateral pressure chan1bers 113 aruj 115 can be
complicated from the rotation—side portions (the crown 107 and
the band 108) U3the fiandsHH—Qde porfions(the uppercover
114 and the lower cover 116). Thereby, the y
resistance can be increased, and the disk friction loss may be
sed. Since disk friction acts in a direction so as to block
energy with which the runner 106 rotates, it is difficult to
improve the efficiency of the hydraulic turbine when the disk
fflcfionlossisincreased.
As a countern1easure to reduce the disk filcfion loss,it
can be taken into t to reduce an outer dian1eter of the
runner106. 'Hfisis based(N1thefactthatthecfiskfflcfionloss
is in proportion to the fifth power of a rotating disk radius.
However, in the case of reducing the outer diameter of the
runner 106, the hydrauHc tuflflne is rnade sxnaHen so that
output of the lic turbine is reduced, and it is difficult to
obtaHidesWed perfinTnance.
[0075]
Furthen as another counternieasure,it can be taken Hmo
t u)rnake adequate a channelarea ofthe back pressure
r 113 or the lateral pressure chamber 115. This is
based on the fact that the disk lloss can be reduced by
decreashugthe channelarea ofthe back pressure chan1ber 113
or the lateral pressure chamber 115. However, if the channel
area is too small, the friction loss of the back pressure or lateral
pressure chan1ber 113 or 115 per se is Hureased, and itis
difficult to make the channel area adequate.
[0076]
Thus, in the present embodiment, to reduce the disk
friction loss, g layers 130 and 131 having hydrophilicity
are provided on the running water surface ce by which the
channel of the running water is defined) of the back pressure
chamber 113 and the running water e of the lateral
pressure chamber 115.
To be more specific, as illustrated in FIGS. 11, 12A, and
128, the back pressure chamber g layer 130 having
hydrophilicity is provided on a e (outer surface) 107a of
the crown 107 which is located in the back pressure chamber
113. The back re chamber coating layer 130 may also
be ed on a surface (inner surface) 114a of the
aforementioned upper cover 114 which is located in the back
pressure chamber 113. Here, the e 107a of the crown
107 which is located in the back pressure chamber 113 and the
surface 114a of the upper cover 114 which is located in the
back pressure chamber 113 constitute the running water
surface of the back pressure chamber 113. The back pressure
chamber coating layer 130 is preferably disposed at a radial
outer side (upstream side) ve to the aforementioned back
pressure chamber—side seal portion 119. That is, the back
pressure chamber coating layer 130 is not preferably formed on
the back pressure chamber—side seal n 119.
Further, the lateral pressure chamber coating layer 131
having hydrophilicity is provided on a surface (outer surface)
108a of the band 108 which is located in the lateral pressure
chamber 115. The lateral pressure chamber coating layer 131
may also be ed on a surface (inner surface) 116a of the
3O lower cover 116 which is located in the lateral pressure chamber
115. Here, the surface 108a of the band 108 which is located
in the lateral pressure chamber 115 and the surface 116a of the
lower cover 116 which is located in the lateral pressure chamber
115 constitute the running water surface of the lateral pressure
chamber 115. The lateral pressure chamber coating layer 131
is preferably disposed at a radial outer side (upstream side)
relative to the aforementioned lateral pressure chamber—side
seal portion 122. That is, the lateral pressure chamber coating
layer 131 is not ably formed on the lateral pressure
chamber-side seal portion 122.
In the present embodiment, the aforementioned back
pressure and l pressure chamber coating layers 130 and
131 are formed by hydrophilic paint. Such hydrophilic paint is
not particularly d as long as it has hydrophilicity. For
example, paint containing a material having a hydrophilic group
(—OH), such as a hydrophilic fluorine material or hydrophilic
ship’s bottom paint, can be properly used. Further, the
hydrophilic paint preferably has a contact angle of, for instance,
40 degrees or less (wherein the contact angle is an angle
formed between a surface of the coating layer 130 or 131 which
is a solid surface and a tangent line to an edge of water being in
contact with the solid surface).
The back pressure chamber coating layer 130 is
preferably provided with a plurality of back pressure chamber
dimples es) 132 open to the back re chamber 113.
The back pressure chamber dimples 132 are formed in a part of
the back pressure chamber coating layer 130 which is nt
to the crown 107 and in a part of the back pressure chamber
coating layer 130 which is adjacent to the upper cover 114.
Similarly, the lateral pressure chamber coating layer 131 is
preferably provided with a plurality of lateral pressure chamber
dimples es) 133 open to the l pressure chamber 115.
The lateral pressure chamber dimples 133 are formed in a part
of the lateral re chamber coating layer 131 which is
adjacent to the band 108 and in a part of the lateral pressure
chamber coating layer 131 which is adjacent to the lower cover
116.
The dimples 132 and 133 are formed in the
corresponding coating layers 130 and 131 in a concave shape
like a small pit. Each of the dimples 132 and 133 preferably
has a depth that is not less than 0.05 times and not more than
0.15 times a diameter of an inscribed circle of each of the
dimples 132 and 133 when the planner shapes of the dimples
132 and 133 have a polygonal shape, or a er of each of
the dimples 132 and 133 when the planner shapes of the
dimples 132 and 133 have a circular shape. Here, as the depth
of each of the dimples 132 and 133 is set to not less than 0.05
times the er, the dimples 132 and 133 can be formed
with high precision. As the depth of each of the dimples 132
and 133 is set to not more than 0.15 times the er, an
increase in friction loss caused by the presence itself of the
dimples 132 and 133 can be ssed. On the other hand,
the planer shape of the dimples 132 and 133 is not particularly
limited, but it is preferably, for instance, a circular shape or a
hexagonal shape. For example, if the diameter of the inscribed
circle of each of the polygonal dimples 132 and 133 or the
diameter (Dd illustrated in A) of each of the circular
dimples 132 and 133 is 1 mm, the depth (Hd illustrated in 12A) of each of the dimples 132 and 133 is preferably not less
than 50 um and not more than 150 pm. A depth of each of the
coating layers 130 and 131 is not particularly limited if the
dimples 132 and 133 can be formed, if the running water
surfaces (the surfaces 107a and 114a located in the back
pressure chamber and the es 108a and 116a located in
the lateral pressure chamber) are not exposed to the s of
the dimples 132 and 133, and if the materials of the coating
layers 130 and 131 can be left .
3O r, an interval between the dimples 132 adjacent to
each other and an interval between the dimples 133 adjacent to
each other are preferably not less than 0.8 times and not more
than 0.12 times the diameter of the inscribed circle of each of
the dimples 132 and 133 when the planner shapes of the
dimples 132 and 133 have the polygonal shape, or the diameter
of each of the dimples 132 and 133 when the planner shapes of
the dimples 132 and 133 have the circular shape. Thereby, an
effect of reducing viscosity resistance of the water flow
according to the dimples 132 and 133 can be effectively
produced, which is experimentally confirmed by the inventors.
For example, if the diameter of the inscribed circle of each of
the polygonal dimples 132 and 133 or the diameter (Dd
illustrated in A) of each of the ar dimples 132 and
133 is 1 mm, the al (G illustrated in A) between
the dimples 132 and the interval (G illustrated in A)
between the dimples 133 are preferably not less than 0.8 mm
and not more than 1.2 mm.
These coating layers 130 and 131 can be formed using,
for instance, a mold 140 having bulges 141 corresponding to
the dimples 132 and 133 of the coating layers 130 and 131 as
illustrated in FIGS. 13A to 13C. In this case, as illustrated in
A, hydrophilic paint is applied to the running water
surface in a film shape at a given thickness first, and a paint
film 134 is formed. Subsequently, as illustrated in 8,
the mold 140 is pressed t the paint film 134 of the
hydrophilic paint. In this case, the mold 140 is pressed such
that the paint film 134 remains between the bulges 141 of the
mold 140 and the running water surface. Next, in the state in
which the mold 140 is pressed, the paint film 134 is dried and
cured. After the paint film 134 is cured, the mold 140 is
removed as illustrated in C. Thereby, it is possible to
obtain the coating layers 130 and 131 in the present
ment. Further, a method of forming the coating layers
130 and 131 is not limited to the aforementioned method. For
e, after the paint film of the hydrophilic paint is cured,
the mold 140 is placed on the cured paint film, and the
hilic paint is applied to the ndings of the bulges
141 of the mold 140, and cured. Thereby, it is also possible to
obtain the coating layers 130 and 131 in the present
embodiment.
Next, an operation of the present embodiment having
such a configuration will be bed.
When a hydraulic turbine operation is conducted in the
Francis turbine 101 according to the present embodiment, as
illustrated in , water flows from the upper reservoir 201
(see ) into the casing 103 through the hydraulic iron
pipe 200. The water flowing into the casing 103 flows from the
casing 103 into the runner 106 through the stay vanes 104 and
the guide vanes 105. Due to the water flowing into the runner
106, the runner 106 is rotatably driven. y, the
generator 111 connected to the runner 106 via the main shaft
110 is driven to generate power. The water flowing into the
runner 106 is discharged from the runner 106 to the lower
reservoir 202 through the draft tube 112. In the meantime,
the guide vanes 105 are rotated. Thereby, the opening degree
of the guide vanes 105 is adjusted, and the capacity of power
generation of the tor 111 is adjusted.
[0086]
While the hydraulic turbine is operated, part of the water
passing through the guide vanes 105 flows into the back
pressure chamber 113. In other words, the water flow flowing
into the back re chamber 113 through the back pressure
chamber—side gap portion 117 ed at the radial outer side
of the crown 107 is formed. Thereby, as illustrated in ,
the water is adapted to be adhered to a surface 135 of the back
pressure chamber coating layer 130, so that a thin water
adhesion layer 136 is formed. The water adhesion layer 136 is
osed between the main flow formed by the running water
located at the center side of the back pressure chamber 113
and the back pressure chamber coating layer 130. Further, the
water forming the water adhesion layer 136 is not at a standstill
with t to the back pressure chamber coating layer 130,
but it has an extremely slow flow velocity. With the
aforementioned configuration, it is possible to reduce the
viscosity ance of the water flow in the proximity of the
back pressure chamber coating layer 130, and to reduce the
friction loss of the running water in the back pressure chamber
113 against the running water surfaces (the surfaces 107a and
114a located in the back pressure chamber).
Further, while the lic turbine is operated, part of
the water passing through the guide vanes 105 flows into the
lateral pressure r 115. In other words, a flow of the
water flowing into the lateral pressure chamber 115 through the
lateral pressure chamber-side gap portion 120 ed at the
radial outer side of the band 108 is formed. Even in this case,
since a water adhesion layer 136 is formed similarly to the back
re chamber 113, it is possible to reduce the ity
resistance of the water flow in the proximity of the lateral
pressure chamber g layer 131, and to reduce the friction
loss of the running water in the lateral pressure chamber 115
against the running water surfaces (the surfaces 108a and 116a
located in the back pressure chamber).
[0088]
The back pressure chamber coating layer 130 is provided
with the a plurality of back pressure chamber dimples 132, and
the lateral pressure chamber coating layer 131 is provided with
the a plurality of lateral pressure chamber s 133.
Thereby, the water in the dimples 132 and 133 is adapted to be
adhered to walls of the dimples 132 and 133 formed by the
hydrophilic paint, and a flow velocity of the water in the dimples
132 and 133 is extremely reduced. Thereby, an effect of
increasing a thickness of the aforementioned water adhesion
3O layer 136 in regions of the running water surfaces in which the
dimples 132 and 133 are ed is obtained. For this ,
it is le to more reduce the viscosity resistance of the
water flow flowing above the dimples 132 and 133, and cause
the running water to smoothly flow on the running water
surfaces.
According to the present embodiment, as described
above, the back pressure chamber coating layer 130 formed by
the hydrophilic paint is provided on the surface 107a of the
crown 107 which is located in the back pressure chamber 113.
Further, the lateral pressure chamber coating layer 131 formed
by the hydrophilic paint is provided on the surface 108a of the
band 108 which is located in the lateral pressure chamber 115.
Thereby, the adhesion layer 136 of the water having an
extremely low flow velocity can be formed on the surfaces of
the coating layers 130 and 131, and the friction loss of the
water flow flowing in the back pressure chamber 113 and lateral
pressure chamber 115 can be reduced. For this reason, it is
possible to reduce the disk friction loss caused by the rotation of
the runner 106. Further, in this case, since the outer diameter
of the runner 106 is not restricted, the outer diameter of the
runner 106 can be decided depending on desired output of the
Francis turbine 101. In on, the disk friction loss can be
reduced regardless of the channel area and shape of the back
pressure chamber 113 or the lateral pressure chamber 115.
Further, according to the present embodiment, as
described above, the back pressure chamber coating layer 130
is provided on the surface 107a of the crown 107 which is
d in the back pressure chamber 113 among the running
water surface of the back pressure r 113. For this
reason, it is possible to effectively reduce the viscosity
resistance of the water flow in the crown—side’s region of the
back pressure chamber 113 which can be vely increased in
3O velocity gradient and is located at the crown 107. se, the
lateral re chamber g layer 131 is provided on the
surface 108a of the band 108 which is d in the lateral
pressure chamber 115 among the running water surface of the
lateral pressure chamber 115. For this reason, it is possible to
effectively reduce the viscosity ance of the water flow in
the band—side’s region of the lateral pressure chamber 115
which can be relatively sed in velocity gradient and is
located at the band 108.
Further, according to the present ment, the back
pressure chamber coating layer 130 is disposed at a radial outer
side relative to the back pressure chamber—side seal portion 119,
and the lateral pressure chamber coating layer 131 is disposed
at a radial outer side ve to the lateral pressure
chamber—side seal n 122. Thereby, it is possible to
prevent the back pressure r coating layer 130 from
being formed at the back pressure chamber—side seal portion
119, and to prevent the lateral pressure chamber coating layer
131 from being formed at the lateral re r-side
seal portion 122. For this reason, it is possible to prevent that
an inflow rate of the water into the back pressure r 113
is increased on the ground that the friction loss of the water
flow is reduced at the back pressure chamber-side seal portion
119 for suppressing the inflow rate of the water from the guide
vanes 105 to the back pressure chamber 113. Similarly, it is
possible to prevent that an inflow rate of the water into the
lateral pressure chamber 115 is increased on the ground that
the friction loss of the water flow is reduced at the lateral
pressure chamber-side seal portion 122 for suppressing the
inflow rate of the water from the guide vanes 105 to the lateral
pressure chamber 115.
Further, according to the present embodiment, the back
pressure chamber coating layer 130 is also ed on the
surface 114a of the upper cover 114 which is located in the
3O back pressure chamber 113, and the l pressure chamber
coating layer 131 is provided on the surface 116a of the lower
cover 116 which is located in the lateral pressure chamber 115.
Thereby, it is possible to more reduce the friction loss of the
water flow flowing in the back pressure chamber 113 and the
lateral pressure chamber 115. Thus, it is possible to more
reduce the disk friction loss caused by the rotation of the runner
106.
In on, ing to the present embodiment, the
back pressure chamber coating layer 130 is provided with the a
plurality of back pressure r dimples 132, and the lateral
pressure chamber coating layer 131 is provided with the a
ity of lateral pressure chamber dimples 133. Thereby, it
is possible to still more reduce the ity resistance of the
water flow in the proximity of the coating layers 130 and 131,
and to more reduce the friction loss of the water flow.
Thus, ing to the present embodiment, it is possible
to reduce the disk on loss to improve the efficiency of the
hydraulic turbine.
[0095]
For example, in the aforementioned embodiment, the
example in which the lic turbine according to the t
invention is applied to the Francis turbine has been described.
However, without being limited thereto, the present invention
can also be applied to other hydraulic turbines except the
Francis turbine. Further, the Francis turbine in the above
embodiment may have a pump operation function of suctioning
up the water of the lower reservoir 202 to pump up it to the
upper reservoir 201.
[0096]
Further, in the above ment, the example in which
the back pressure chamber coating layer 130 is provided on the
running water surface of the back pressure chamber 113, and
the lateral pressure chamber coating layer 131 is provided on
3O the running water surface of the lateral pressure chamber 115
has been described. However, without being limited thereto,
any one of the back pressure chamber coating layer 130 and the
lateral pressure chamber coating layer 131 may be provided,
and the other may not be provided. Even in this case, it is
possible to reduce the disk friction loss caused by the rotation of
the runner 106.
In addition, in the above embodiment, the example in
which the coating layers 130 and 131 are formed by the
hydrophilic paint has been described. r, without being
d thereto, if the base material such as the crown 107 or
the band 108 of the runner 106, the upper cover 114, or the
lower cover 116 or the like is formed of aluminum, the coating
layers 130 and 131 may be formed by, for instance, boehmite
treatment. In this case, an aluminum hydrated oxide film may
be formed on a running water surface ce) of the base
material, and the coating layers 130 and 131 can have
hydrophilic.
(Sixth embodiment)
Next, a pipe in a sixth embodiment will be described
using FIGS. 15 and 16.
In the sixth embodiment illustrated in FIGS. 15 and 16, a
main difference is that a coating layer formed by hydrophilic
paint is ed on a running water e of the pipe, and
other configurations are approximately identical to those of the
first embodiment illustrated in FIGS. 1 to 4. In FIGS. 15 and
16, the same parts as in the first embodiment rated in
FIGS. 1 to 4 are given the same symbols, and ed
description thereof will be omitted.
In the present embodiment, reference will be made to a
Francis turbine 1 given as an example of a hydraulic turbine,
and to a hydraulic iron pipe 200 that is given as an example of
3O the pipe and guides water from an upper reservoir 201 to a
casing 3 (see FIGS. 1 and 10) of the Francis turbine 1.
As illustrated in , the hydraulic iron pipe (pipe)
200 in the present embodiment is configured to be connected to
the casing 3 of the Francis turbine 1, and to guide the water
from the upper reservoir 201 to the casing 3 of the Francis
turbine 1 during hydraulic e operation. The water flowing
out of the Francis turbine 1 is adapted to be guided to a lower
reservoir 202.
As rated in , the hydraulic iron pipe 200 is
equipped with a pipe body 210 and a running water surface 212
that is provided for the pipe body 210 and defines a channel
211 for water. Among them, the running water surface 212 is
provided with a coating layer 213 formed by hydrophiiic paint,
and the g layer 213 is provided with a plurality of (or
multiple) dimples 214 open to the channel 211. The coating
layer 213 and the s 214 may be equally formed with the
same configuration as the coating layer 60 and the dimples 61
described in the aforementioned fourth embodiment or the
g layers 130 and 131 and the dimples 132 and 133
described in the aforementioned fifth embodiment. Further, if
the pipe body 210 is formed of aluminum, the coating layer 213
can be formed by, for instance, boehmite treatment.
Thus, according to the present embodiment, the coating
layer 213 formed by the hydrophiiic paint is provided on the
running water surface 212. Thereby, an adhesion layer 62 (see
of the water having an extremely low flow velocity can
be formed on a surface of the coating layer 213, and a friction
loss of a water flow flowing in the channel 211 defined by the
running water e 212 can be reduced. For this reason, it
is possible to prevent energy of the water flowing into the
casing 3 of the Francis turbine 1 from being dissipated, and to
make good use of the energy of the water to e efficiency
3O of the hydraulic turbine.
Further, according to the present embodiment, the
g layer 213 is provided with the a plurality of dimples 214.
Thereby, it is possible to more reduce viscosity resistance of the
water flow in the proximity of the g layer 213 and to more
reduce the friction loss of the water flow.
In the entioned present ment, the e
in which the pipe is the hydraulic iron pipe 200 connected to the
Francis turbine 1 has been described. r, the pipe
connected to the hydraulic e is not limited to the hydraulic
iron pipe 200 connected to the Francis e 1, and thus the
present invention may be applied to an arbitrary pipe connected
to an arbitrary hydraulic turbine.
According to the aforementioned embodiment, it is
possible to reduce the friction loss to make good use of the
energy of the water.
While certain embodiments of the present invention have
been described, these embodiments have been presented by
way of example only, and are not intended to limit the scope of
the inventions. Indeed, the novel embodiments may be
embodied in a variety of other forms; rmore, various
omissions, substitutions and changes in the form of the
embodiments described herein may be made without departing
from the spirit of the inventions. The accompanying claims and
their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions. Further, it will be understood that these
embodiments can be at least partially combined properly
without departing from the gist of the present invention.
Furthermore, in the above embodiments, the e in which
the hydraulic turbine according to the present ion is
applied to the Francis turbine has been described. However,
3O without being limited thereto, the present invention may be
applied to other hydraulic turbines except the Francis turbine.
Claims (11)
1. A lic e comprising: a turbine body having a runner configured to be rotated by water flowing therein during hydraulic turbine ion, and a guide vane configured to adjust a flow rate of the water flowing into the runner; a running water surface provided in the turbine body, the running water surface defining a channel for water; and a coating layer provided on the running water surface, the coating layer being formed by hydrophilic paint.
2. The hydraulic turbine according to claim 1, wherein the coating layer includes a plurality of dimples open to the channel.
3. The hydraulic turbine according to claim 1 or 2, wherein: the turbine body has upper and lower covers opposite to each other, the guide vane is ed between the upper cover and the lower cover, the guide vane being rotatably supported by the upper and lower covers; the running water e provided for the upper cover and the running water surface provided for the lower cover each have a tive cover ating region in which the coating layer is not provided; and the cover non-coating region is formed to include rotation region of the guide vane when viewed in a direction taken along a rotational axis of the guide vane.
4. The hydraulic turbine according to any one of claims 1 to 3, wherein: the runner of the turbine body includes a plurality of runner blades; the running water surface provided for each runner blade has an upstream non-coating region in which the coating layer is not provided; and the upstream non-coating region is formed at upstream ends of pressure and n surfaces of the running water surface of each runner blade during hydraulic turbine operation.
5. The lic turbine according to claim 4, n, when an outlet diameter of the runner during the hydraulic turbine operation is defined as De, a length (Li) of the am non-coating region in a main flow direction is given as s: Li/De £ 0.8.
6. The hydraulic turbine according to any one of claims 1 to 5, n: the runner of the turbine body includes a plurality of runner ; the running water surface provided for each runner blade has a downstream non-coating region in which the coating layer is not provided; and the downstream non-coating region is formed at a downstream end of a suction surface of the running water surface of each runner blade during the hydraulic turbine operation.
7. The hydraulic turbine according to claim 6, wherein, when an outlet diameter of the runner during the hydraulic turbine operation is d as De, a length (Lo) of the downstream non-coating region in a main flow direction is given as follows: Lo/De £ 0.8.
8. The hydraulic turbine according to claim 2, wherein the dimples have a depth that is not less than 0.05 times and not more than 0.15 times a diameter of an inscribed circle of each dimple when the planar shape of each dimple is a polygonal shape, or a diameter of each dimple when the planar shape of each dimple is a circular shape.
9. The hydraulic turbine according to claim 2, wherein an interval between the dimples adjacent to each other has not less than 0.8 times and not more than 1.2 times a diameter of an inscribed circle of each dimple when the planar shape of each dimple is a polygonal shape, or a er of each dimple when the planar shape of each dimple is a circular shape.
10. The hydraulic turbine according to claim 2, wherein the dimple has a depth of not less than 50 mm and not more than 150 mm.
11. The hydraulic turbine according to claim 1, substantially as herein described with reference to any one of the embodiments shown in the accompanying
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ70089414A NZ700894A (en) | 2013-08-20 | 2014-07-28 | Hydraulic turbine |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013170681 | 2013-08-20 | ||
JP2013-170681 | 2013-08-20 | ||
JP2014035828 | 2014-02-26 | ||
JP2014-035828 | 2014-02-26 | ||
JP2014-137072 | 2014-07-02 | ||
JP2014137072A JP6382603B2 (en) | 2013-08-20 | 2014-07-02 | Water wheel |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ627914A NZ627914A (en) | 2015-03-27 |
NZ627914B true NZ627914B (en) | 2015-06-30 |
Family
ID=
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