Note: Descriptions are shown in the official language in which they were submitted.
CA 02224054 1998-02-13
-1-
SPECIFICATION
WATER PUMPING APPARATUS UTILIZING COMPRESSED AIR
Technical Field
This invention relates to a water pumping apparatus for use in
hydroelectric power generation utilizing the expansion energy of compressed
air.
Technical Background
Energy available in the world relies heavily on coal, petroleum and
nuclear power, the use of which often results in environmental destruction.
On the other hand, hydroelectric power, wind power or wave power not
producing any material resulting in environmental destruction has little or
no prospect of great development.
Disclosure of the Invention
The present invention is based on a method for producing compressed air
which utilizes three physical properties, i.e. the fact that a substance at a
high
position has a higher potential energy than a substance at a low position,
that
buoyancy acts on a substance in fresh water and that hydraulic pressure
CA 02224054 1998-02-13
-2-
increases in proportion of the depth of water. In a specific embodiment of the
method, a container having air sealed therein on the water surface is sunk
deep under water by using a weight having a larger specific gravity than
water, thereby compressing the air sealed in the container by means of
hydraulic pressure, the weight is caused to be free from the container to
allow
the container having the compressed air sealed therein to float on the water
by the action of buoyancy of a buoyant body, and then the compressed air is
recovered from the container. Thus, the present invention uses specific
gravity, hydraulic pressure and buoyancy, all obtained from natural resources.
The present invention provides a water pumping apparatus for use in
hydraulic power generation utilizing the expansion energy of the compressed
air produced by the aforementioned method and apparatus, in which the
expansion energy of the aforementioned compressed air can be applied to a
hydroelectric power generating apparatus. In this case, the water once
subjected to power generation can be repeatedly recycled. Therefore, according
to the present invention, the hydraulic power generation otherwise limited
by the amount of rain water can be utilized to the maximum possible extent.
In addition, the hydroelectric power generation can be applied to private
power generation in a multistorey building, for example.
More specifically, the present invention provides a water pumping
apparatus utilizing compressed air for use in hydroelectric power generation,
which comprises:
CA 02224054 1998-02-13
-2a-
a container situated below the level of the water surface of a downstream
reservoir for storing water subjected to hydroelectric power generation using
water in an upstream reservoir;
a piston slidably accommodated within said container for dividing an
inner space of said container into a water tank chamber and an air expansion
chamber;
a water inlet tube connected to said water tank chamber via a first control
valve for regulating the flow rate of the water supplied from the downstream
water reservoir into said water tank chamber;
a water feed pipe connected to said water tank chamber via a second
control valve for regulating the flow rate of the water fed under pressure
from said water tank chamber into the upstream water reservoir; and
a recovery vessel containing compressed air therein and connected via a
flow regulating valve to said air expansion chamber for discharging the
compressed air contained in said recovery vessel into said air expansion
chamber to cause said piston to slide in a direction of increasing a volume of
said air expansion chamber.
CA 02224054 1998-02-13
-3-
Brief Explanation of the Drawings
Figure I is a longitudinally sectioned side view showing
an apparatus for producing compressed air, with a clamping
device omitted from illustration.
Figure 2 is a longitudinally sectioned side view, similarly
to Figure l, showing an apparatus for producing compressed air,
with a compressed air recovery vessel omitted from illustration.
Figure 3 is a longitudinally sectioned side view showing
another embodiment of the apparatus for producing compressed air,
Figure 4 is a longitudinally sectioned side view showing
a water pumping apparatus for use in hydroelectric power
generation utilizing the compressed air,
Figure 5 is a similar, longitudinally sectioned side view
showing another embodiment of the water pumping apparatus.
Best Mode for Working the Invention
Figure l, Figure 2 and Figure 3 are longitudinally
sectioned side views illustrating an apparatus for producing
CA 02224054 1998-02-13
-4-
compressed air. The compressed air producing apparatus 1
includes a container body 10 which has an air chamber 12 capable
of sealing air therein and is capable of reducing its volume by
hydraulic pressure, a compressed air recovery vessel 30
connected to the air chamber via a check valve 32 and adapted
to receive the compressed air therein when the volume of the
air chamber 12 is reduced by hydraulic pressure, and a weight 40
mounted on the container body 10 and adapted to sink the
container body 10 and recovery vessel 30 deep under water.
The air chamber 12 has a construction such that its volume
can be reduced by hydraulic pressure when it is sunk under water.
In the air chamber 12 of the apparatus shown in Figure 1 and
Figure 2, a compression piston 14 is disposed in the sealed
cylindrical container body 10 has so as to be slidable upward
and downward along the inner wall of the container body 10 and
divide the interior of the container body 10 into the sealed air
chamber and a water chamber 16 formed with a plurality of water
inlet ports 18 opening to the peripheral wall of the container
body for introducing water into the container body 10 from the
outside. When the container body 10 is caused to sink deep
under water, the external water enters the water chamber 16
disposed on the upper side of the compression piston 14 through
the water inlet ports 18 under pressure. The compression piston
CA 02224054 1998-02-13
-5-
14 is urged toward the air chamber 12 by the hydraulic pressure
of the water entering the water chamber 16 to thereby compress
the air in the air chamber 12. The air chamber 12 is connected
to a compressed air recovery vessel 30 through a connecting
tube 34. The connecting tube 34 is provided with a check valve
32. The compressed air recovery vessel 30 has a very small
volume compared with that of the air chamber 12 before it is
reduced in volume, so that the compressed air can be maintained
intact, The check valve 32 acts such that when the pressure in
the air chamber 12 is higher than that in the compressed air
recovery vessel 30, the air in the air chamber 12 is permitted
to flow into the air recovery vessel 30 and such that when the
pressure relation is reversed, the compressed air in the air
recovery vessel 30 does not flow back into the air chamber 12.
The recovery vessel 30 can be detached from the container body
for replacement.
Figure 3 shows another example of the air chamber 12. In
the air chamber 12, the outer wall of the cylindrical container
body 10 can be deformed to be expanded and contracted in the
vertical direction by the external hydraulic pressure. The
inside space of the container body 10 serves as an air chamber
12. When the outer wall is contracted in the vertical
direction by the external hydraulic pressure, the volume of the
CA 02224054 1998-02-13
'
air chamber 12 can be reduced, The structure of the container
body 10 will be described in more detail. The container body 10
is constructed in a sealed state such that an upper plate 21
and a lower plate 22 are joined together through a cloth
material 24 and such that annular reinforcement members 26
are sewn to the cloth member 24 so that it is expanded into a
cylindrical configuration when air having a higher pressure than
the atmospheric pressure is introduced into the air chamber,
The cloth material 24 is formed of a material which is strong
in tensile stress and is both water and air impermeable. The
reinforcement members 26 are strong against a compressive force
and are hardly deformed. The container body 10 is provided
with an air inlet valve 28 adapted to take air into the air
chamber 12. The upper plate 21 of the container body 10 is
connected to a compressed air recovery vessel 30 via a
connecting tube 34, The connecting tube 34 is provided with a
check valve 32 which has the same function as the check valve 32
provided on the apparatus shown in Figure 1 and Figure 2, The
compressed air recovery vessel 30 shown in Figure 3 serves
concurrently as a buoyant body. This will be described later,
Although the container body 10 shown in Figure 3 has a hollow
cylindrical configuration, it is preferable that it has a hollow
spherical configuration so that it can bear the hydraulic
CA 02224054 1998-02-13
_7_
pressure of the deep sea.
A weight 40 is attached to any of the container bodies 10
in order to sink the container body 10 deep under water. The
weight 40 is detachably mounted on the container body 10 by a
weight mounting device 42 when the volumeof the air chamber 12
is reduced to the maximum possible extent by hydraulic pressure.
Any of the container bodies 10 is further provided with the
buoyant body 70 so that it can float on the water by means of
buoyancy when the sink weight 40 has been detached from the
container body 10.
The weight mounting device 42 is constructed such that the
weight 40 is detached from the container body 10 when the volume
of the air chamber 12 is reduced to the maximum possible extent,
i.e, when the the leading end portion of the compression piston
I4 comes into contact with the bottom of the air chamber 12 in
the apparatus shown Figure 1 and Figure 2 or when the upper and
lower plates 21 and 22 come into contact with each other in the
apparatus shown in Figure 3.
In the apparatus shown in Figure 1 and Figure 2, the weight
mounting device 42 comprises a casing 44 for accommodating the
weight 40 therein and having a bottom portion 46 capable of
being opened by its own weight and a clamping device 50 for
clamping a wire 48 extending over the bottom portion 46 so as
CA 02224054 1998-02-13
not to open accidentally, The casing 44 depends downward from
the container body 10.
The clamping device 50 will be explained. Reference
numeral 52 designates wrench-like holding metal pieces 52
which have clamp portions and proximal portions pivoted on a
pin 54, When the proximal portions are away from each other,
the clamp portions are also away from each other. One of the
proximal portions is fixed to a lower part of the container body
10, whereas the other of the proximal portions is left free.
Between the proximal portions a spring body 56 is interposed
for biasing the free proximal portion in a direction away from
the fixed proximal portion, A lock lever 58 is provided to
lock the free proximal portion so as not to be moved away from
the fixed proximal end by the biasing force of the spring body
56. Reference numeral 60 designates an unlocking pin having an
upper end thereof projecting from the bottom into the inside of
the air chamber 12 and the lower end thereof engaged with the
lock lever 58. Therefore, when the upper end of the unlocking
pin 60 is depressed, the lock lever 58 is unlocked and, as a
result, the free proximal end of the holding metal piece 52 is
biased by the biasing force of the spring body 56 in the
direction away from the fixed proximal end to open the clamp
portions, Consequently, when the volume of the air chamber 12
CA 02224054 1998-02-13
-9-
is reduced to the maximum possible extent and the leading end
of the compression piston 14 reaches the bottom of the air
chamber 12, the unlocking pin 60 is depressed to unlock the
lock lever 58 and the clamp portions of the holding metal piece
52 is opened, When the clamped wire 48 is released from the
clamp portions, the bottom portion 46 of the casing 44 is opened
by its own weight, whereafter the weight 40 is discharged out
of the casing 44. Gravel on the seashore can be used as the
weight 40.
In the embodiment of Figure 3, the weight mounting device
42 is constituted of a clamping device 50 from which a weight 40
is directly suspended, This clamping device 50 have the same
structure and the same weight-releasing function as that shown
in Figures 1 and 2. The weight 40 shown in Figure 3 is formed
of a bag filled with gravel,
In the apparatus shown in Figures 1 and 2, both the
container body 10 and the casing 44 are provided with buoyant
chambers acting as the buoyant body 70. Since a compressed
stress applied to the buoyant chambers 70 becomes larger in
proportion as the apparatus sinks deeper under water, the
structural members constituting the buoyant chambers are
required to be rigid, In order to make the difference between
the internal pressure and the external pressure as small as
CA 02224054 1998-02-13
- 10 '
possible at the water level which the apparatus reaches, it is
desirable to fill the buoyant chambers with compressed air in
advance.
In the apparatus of Figure 3, the compressed air recovery
vessel 30 serves concurently as the buoyant body 70 which has a
hollow spherical configuration and is connected to an upper
portion of the container body 10 via rods 72.
It is structurally desirable to fill the buoyant chambers
70 with compressed air in advance as described above because
they can bear the water pressure even under the deeper water.
Due to the dual function of the recovery vessel 30, the pressure
of the air contained therein is increased by repeating the
recovery operation in view of the volume of the recovery vessel
30 and, therefore, the apparatus of Figure 3 can bear the higher
hydraulic pressure in deeper water and can be suitably used for
obtaining a compressed air of high pressure.
The operation of the apparatus of Figures 1 and 2 will now
be described. The compression piston is pulled to the highest
position and then the air recovery vessel 30 is attached to the
container body. After the bottom portion 46 of the casing 44
is closed, the weight 40 such as gravel is introduced into the
casing 44, The casing 44 is then attached to the lower part of
the container body 10. Thereafter the apparatus is hung above
CA 02224054 1998-02-13
the surface of the sea by means of a hanging chain not shown and
then separated from the hanging chain. As a result, the whole
apparatus is sunk deep under the water by gravity, At that
time, water flows into the water chamber 16 through the water
inlet ports 18 due to hydraulic pressure to push the compression
piston 14 down, thereby compressing the air in the air chamber
12. The hydraulic pressure increases as the apparatus sinks
deeper, and the lower end of the compression piston 14 is
eventually brought to the bottom portion of the air chamber 12,
Thus, all air in the air chamber 12 is inserted into the
recovery vessel 30 under pressure. Since the recovery vessel 30
is provided with the check valve 32, a decrease of air pressure
in the air chamber 12 does not cause the compressed air in the
recovery vessel 30 to flow back to the air chamber 12, When
the lower end of the compression piston 14 reaches the bottom
portion of the air chamber 12, the clamped state of the clamping
device 50 is released and the bottom portion 46 of the casing 44
is opened to drop the weight 40. As a result, the buoyancy acts
on the whole apparatus due to the function of the buoyant
chambers 70 and the whole apparatus floats to the surface of the
sea automatically, thus producing compressed air,
Operation of the apparatus shown in Figure 3 will now be
described.
CA 02224054 1998-02-13
- 12 -
The air inlet valve 28 of the container body 10 is opened
and the weight 40 is attached to the lower plate 22, When the
apparatus with the upper plate 21 directed upward is hung by a
crane, air automatically flows into the air chamber 12 of the
container body 10 through the air inlet valve 28 owing to the
function of the weight 40 to expand the container body 10 into
a cylindrical configuration, Then, the valve 28 is closed.
The weight 40 is attached to the clamping device 50 which is the
weight mounting device 42. The whole apparatus is slowly
lowered onto the surface of water and separated from the
crane. The whole apparatus slowly sinks under water. When the
hydraulic pressure increases as the apparatus sinks deep under
water, air in the air chamber 12 is compressed and the air
chamber 12 is reduced in volume. However, the air chamber is
not reduced in size in the horizontal direction because of the
presence of the annular reinforcement members 26, but is in the
vertical direction, and consequently exhibits a vertically
compressed appearance as a whole. As a result, air in the air
chamber 12 is compressed to an extent that the internal pressure
is substantially equal to the external hydraulic pressure, and
part of the compressed air is stored in the air recovery vessel
30. As the apparatus sinks deeper, the volume of the air
chamber 12 is further reduced by the hydraulic pressure and
CA 02224054 1998-02-13
- 13 -
most of the air in the air chamber 12 is inserted under pressure
into the air recovery vessel 30. At the same time, a projection
62 attached to the upper plate 21 pushes down the unlocking pin
60 mounted on the lower plate 22 to release the locked state of
the lock lever 58, and the clamping portion of the holding
metal piece 52 is opened by means of the biasing force
of the
spring body 56 to release the weight 40. When the weight has
40
been detached from the apparatus, the whole apparatus to
begins
float upwardly owing to the buoyant function of the recovery
vessel 30. At this time, since the recovery vessel 30 a
keeps
high pressure due to the provision of the check valve is
32, it
lifted by the crane when it finally floats on the surface
of
the water. Thus, the recovery vessel is recovered, When
the
air inlet valve 28 is opened, air flows into the air chamber12
to restore the apparatus to its original shape. By repeating
the above processes without removing the air recovery 30
vessel
from the container body 10, the amount of compressed air
corresponding to the volume of the recovery vessel 30
can be
recovered,
Figures 4 and 5 show a water pumping apparatus for use
in
hydroelectric power generation utilizing the compressed
air
produced by the aforementioned compressed air production
apparatus,
CA 02224054 1998-02-13
- 14 -
The water pumping apparatus of Figure 4 comprises a
container 84 disposed between an upstream water reservoir 80 of
a hydroelectric power generating apparatus and a downstream
water reservoir 82 for reserving used water, The interior of
the container 84 is divided into an upper water tank chamber 88
and a lower air expansion chamber 90 by a piston 86 which is
slidable in the vertical direction within the container 84,
The water tank chamber 88 is connected to a water inlet tube 92
for flowing water into the water tank chamber 88 from the
downstream water reservoir 82 and also to a water feed tube 94
for feeding under pressure the water reserved in the chamber 88
to the upstream water reservoir 80, The air expansion chamber
90 is provided with an air recovery vessel 30 containing
compressed air for pushing up the piston 86 in order to expand
the volume of the air expansion chamber 90, The recovery vessel
30 contains the compressed air recovered by the aforementioned
compressed air producing apparatus, Between the air recovery
vessel 30 and the air expansion chamber 90, a first control
valve 96 is disposed. By adjusting the first control valve 96,
the amount of compressed air to be discharged into the air
expansion chamber 90 from the recovery vessel 30 is regulated.
In the drawing, reference numeral 98 denotes a second control
valve disposed at the water inlet tube 92, numeral 100 denotes
CA 02224054 1998-02-13
- 15 -
a third control valve disposed at the water feed tube 94, and
numeral 102 denotes a fourth control valve disposed at an air
vent pipe. These valves are operated to control the flow of
water or air,
The water pumping apparatus of Figure 5 comprises a
container 110 disposed between an upstream water reservoir 80
of a hydroelectric power generating apparatus and a downstream
water reservoir 82 for reserving the used water, The interior
of the container 110 is divided by a partition wall 112 into a
water tank chamber 114 and an air expansion chamber 116 which
communicates with each other at the lower part of the container
110, The water tank chamber 114 is connected to a water inlet
tube 92 for flowing water into the water tank chamber 114 from
the downstream water reservoir 82 and also to a water feed tube
94 for feeding under pressure the water reserved in the chamber
114 to the upstream water reservoir 80. The air expansion
chamber 116 is provided with a recovery vessel 30 containing
compressed air for expanding the volume of the air expansion
chamber, The apparatus of Figure 5 is designed such that air
bubbles of the compressed air to be discharged into the
container 110 from the recovery vessel 30 rise upward by means
of buoyancy and are pooled in the air expansion chamber 116
divided by the partition wall 112, The remaining construction
CA 02224054 1998-02-13
- 16 -
thereof is the same as that of the apparatus of Figure 4,
The operation of the water pumping apparatus shown in
Figures 4 and 5 will be described,
First, used water, i,e, water already subjected to
hydroelectric generation, is caused to flow into the water tank
chamber 88 or 114 from the downstream water reservoir 82 through
the water inlet tube 92 until the water tank chamber 88 or 114
is filled with the water, The air in the air expansion chamber
90 or 116 is all drafted by opening the fourth control valve 102.
The second and fourth control valves 98 and 102 are closed,
while the third control valve 100 is opened, The first control
valve 96 of the recovery vessel 30 is mounted to air expansion
chamber 90 or 116 in a slightly open state, The apparatus of
Figure 4 represents a case where the piston is used, Since the
pressure of compressed air discharged from the recovery vessel
30 is much greater than the hydraulic pressure in the water tank
chamber 88, it pushes the piston 86 upward, The apparatus of
Figure 5 represents a case where the piston is not used, Air
bubbles of the compressed air discharged from the recovery
vessel 30 rise in the water filled in the water tank chamber 114
while expanding its volume and are pooled in the air expansion
chamber 116. In either case, the volume of the air expansion
chamber 90 or 116 is gradually increased, Water rises through
CA 02224054 2001-05-22
- 17 -
the water feed tube 94 by the amount equivalent to the increased
volume of the air expansion chamber, When the tube 94 has been
filled with water, the water flows into the upstream water
reservoir 80, When the discharge of the compressed air from
the recovery vessel 30 has been substantially stopped, the
third control valve 100 is closed and the fourth control valve
102 is opened to draft air, and the second control valve 98 is
opened to introduce the water which has already been subjected
to hydroelectric power generation into the water tank chamber 88
or 114. When all air in the air expansion chamber 90 or 116 has
been drafted, the second and fourth control valves 98 and 102
are closed, a new recovery vessel 30 is attached, the third
control valve 100 is opened and then the aforementioned
procedure is repeated. By repeating the aforementioned
procedure, water which has already been subjected to hydro-
electric power generation can be sent back to the upstream water
reservoir 80, so that it can be repeatedly used for hydro-
electric power generation.
In the embodiment of FIG. 4 it is noted that an air
diffusing space 120 is provided so as to communicate with the
air expansion chamber, the air expansion chamber being
separated from the water tank chamber by the piston 86. A
nozzle exit of the recovery vessel 30 and the valve 96 thus
has flow therethrough diffused by the air diffusing 120 as the
flow enters the air expansion chamber 90.
CA 02224054 2001-05-22
- 17a -
Thus, the present invention enables highly compressed air
to be provided in the recovery vessel, compressed to the
extent that a high speed flow of air will exit from the nozzle
exit into the expansion chamber 90. In the case of the
embodiment of FIG. 4, thus, the air is first diffused in the
air diffusing space 120, in which space the jetted air
increases its specific volume and decreases its pressure, the
air consequently being discharged to the air expansion chamber
90.
Applicability of the Invention to the Industry
As described in the foregoing, the energy required by the
method and apparatus for producing compressed air according to
the present invention is the gravity of a weight, hydraulic
,..,.".~.,~~"~..o "-,~ y",.~,..~,-,l,o a'1~ nl-,t-a;nar9 frnm natmral
resrn~rces_
CA 02224054 1998-02-13
- 18 -
In addition, according to the water pumping apparatus for
use in hydroelectric power generation utilizing the compressed
air obtained by the compressed air producing method and
apparatus of the present invention, the water used in hydro-
electric power generation can be repeatedly returned to an
upstream water reservoir not subject to power generation by
making use of the expansion energy of the compressed air.
Therefore, the hydraulic power generation otherwise limited by
the amount of rain water can be utilized to the maximum possible
extent, In addition, the hydroelectric power generation can be
applied to private power generation in a multistory building,
for example.
Furthermore, the air expansion energy of the compressed air
obtained by the aforementioned compressed air prodeucing method
and apparatus can be used in the form of power for driving and
propelling vehiclles or as cooling means utilizing the phenome-
non that when gas is expanded it absorbs the environmental heat,
When the compressed air is mixed with fuel in an internal
combusion engine, the amount of the fuel can be reduced. The
compressed air is also applicable to a sprayer, Thus, since the
air exspansion energy of the comoressed air can be converted
into various kinds of energy, the present inventioncan reduce
the amount of fossil fuels used at present to a great extent,
