U.S. patent application number 13/953076 was filed with the patent office on 2014-03-20 for power generating apparatus and operation method thereof.
This patent application is currently assigned to Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.). The applicant listed for this patent is Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.). Invention is credited to Shigeto Adachi, Masayoshi Matsumura, Yutaka Narukawa.
Application Number | 20140075941 13/953076 |
Document ID | / |
Family ID | 48915899 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140075941 |
Kind Code |
A1 |
Adachi; Shigeto ; et
al. |
March 20, 2014 |
POWER GENERATING APPARATUS AND OPERATION METHOD THEREOF
Abstract
Provided is a power generating apparatus capable of using power
generated by a heat engine in combination with power of a driving
source provided separately from the heat engine. In order to
prevent a problem caused when activating and stopping the
apparatus, the apparatus of the present invention includes a rotary
machine driving source which generates a rotational driving force
for a rotary machine and a heat engine which drives the rotary
machine in cooperation with the rotary machine driving source,
wherein the heat engine includes an expander which expands an
evaporated working medium so as to generate a rotational driving
force, the expander is provided with a bypass pipe which causes a
working medium inlet of the expander to communicate with a working
medium outlet thereof, and the bypass pipe is provided with an
on-off valve which opens and closes the bypass pipe.
Inventors: |
Adachi; Shigeto;
(Takasago-shi, JP) ; Matsumura; Masayoshi;
(Takasago-shi, JP) ; Narukawa; Yutaka;
(Takasago-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) |
Kobe-shi |
|
JP |
|
|
Assignee: |
Kabushiki Kaisha Kobe Seiko Sho
(Kobe Steel, Ltd.)
Kobe-shi
JP
|
Family ID: |
48915899 |
Appl. No.: |
13/953076 |
Filed: |
July 29, 2013 |
Current U.S.
Class: |
60/646 ; 60/657;
60/661; 60/670; 60/676 |
Current CPC
Class: |
F01K 3/242 20130101;
F01K 23/16 20130101; F01K 15/00 20130101; F01K 23/04 20130101; F01K
13/02 20130101; F01K 23/08 20130101 |
Class at
Publication: |
60/646 ; 60/670;
60/661; 60/676; 60/657 |
International
Class: |
F01K 13/02 20060101
F01K013/02; F01K 3/24 20060101 F01K003/24 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2012 |
JP |
2012-203220 |
Oct 19, 2012 |
JP |
2012-232032 |
Claims
1. A power generating apparatus comprising: a rotary machine
driving source which generates a rotational driving force for a
rotary machine; and a heat engine which drives the rotary machine
in corporation with the rotary machine driving source, wherein the
heat engine includes an expander which expands an evaporated
working medium so as to generate a rotational driving force,
wherein the expander is provided with a bypass pipe which causes a
working medium inlet of the expander to communicate with a working
medium outlet thereof, and wherein the bypass pipe is provided with
an on-off valve which opens and closes the bypass pipe.
2. The power generating apparatus according to claim 1, further
comprising: a control device which controls an opening and closing
operation of the on-off valve, wherein when activating the rotary
machine driving source and the heat engine, the control device
performs control which opens the on-off valve so that the working
medium flows into the bypass pipe, activates the rotary machine
driving source, and closes the on-off valve when it is determined
that the working medium flowing into the expander is
evaporated.
3. The power generating apparatus according to claim 2, further
comprising: a suction pressure detector which detects a suction
pressure of the expander, wherein the control device determines
that the working medium flowing into the expander is evaporated
when a pressure value detected by the suction pressure detector
becomes a predetermined pressure value or more.
4. The power generating apparatus according to claim 2, further
comprising: a suction pressure detector which detects a suction
pressure of the expander; and an discharge pressure detector which
detects an discharge pressure of the expander, wherein the control
device determines that the working medium flowing into the expander
is evaporated when a differential pressure between a pressure value
detected by the suction pressure detector and a pressure value
detected by the discharge pressure detector becomes a predetermined
value or more.
5. The power generating apparatus according to claim 2, wherein the
rotary machine is a gas compressor, wherein the power generating
apparatus further comprises a temperature detector which detects an
exhaust gas temperature of the gas compressor, and wherein the
control device determines that the working medium flowing into the
expander is evaporated when a temperature value detected by the
temperature detector becomes a predetermined temperature value or
more.
6. The power generating apparatus according to claim 2, wherein the
control device includes a time measuring unit which measures an
elapse time from the activation of the rotary machine driving
source, and wherein the control device determines that the working
medium flowing into the expander is evaporated when the elapse time
detected by the time measuring unit becomes a predetermined time or
more.
7. The power generating apparatus according to claim 1, further
comprising: a control device which controls an opening and closing
operation of the on-off valve, wherein when stopping the rotary
machine driving source and the heat engine, the control device
performs control which opens the on-off valve so that the working
medium flows into the bypass pipe and the driving operation of the
expander is stopped.
8. The power generating apparatus according to claim 1, further
comprising: a control device which controls an opening and closing
operation of the on-off valve, wherein when the rotary machine
driving source is stopped under the state where the rotary machine
driving source and the heat engine are normally operated, the
control device performs control which opens the on-off valve so
that the working medium flows into the bypass pipe and the driving
operation of the expander is stopped.
9. The power generating apparatus according to claim 1, wherein the
rotary machine is a compressor which compresses a gas supplied
thereto in a high pressure state and the rotary machine driving
source is a motor, and wherein heat of a high-pressure gas produced
by the compressor is used as a heat source for a working medium in
an evaporator of the heat engine.
10. The power generating apparatus according to claim 1, wherein
the rotary machine driving source is a second expander which
generates power by expanding a heating medium as steam, and wherein
an evaporator of the heat engine heats and evaporates the working
medium by the heating medium expanded by the second expander.
11. The power generating apparatus according to claim 10, further
comprising: a first shaft portion which is connected to a rotary
shaft of the heat engine; a second shaft portion which is connected
to a rotary shaft of the second expander; and a coupling portion
which couples the first shaft portion and the second shaft portion
to each other so that a driving force is transmitted through the
coupled shaft portions, wherein the coupling portion is configured
as a speed increasing and decreasing mechanism which is provided
between the first shaft portion and the second shaft portion so as
to change a rotation speed.
12. The power generating apparatus according to claim 10, wherein
water used in a condenser of the heat engine or water condensed
from the steam in the evaporator of the heat engine is supplied as
lubricant to a bearing of the rotary shaft of the second
expander.
13. The power generating apparatus according to claim 1, further
comprising: a first shaft portion which is connected to a rotary
shaft of the heat engine; a second shaft portion which is connected
to a rotary shaft of the rotary machine driving source; and a
coupling portion which couples the first shaft portion and the
second shaft portion to each other so that a driving force is
transmitted through the coupled shaft portions, wherein at least
one of the first shaft portion and the second shaft portion is
accommodated inside a hermetic body, and wherein the coupling
portion is configured as a magnetic coupling which magnetically
couples the first shaft portion and the second shaft portion to
each other.
14. A method of operating the power generating apparatus according
to claim 1, wherein when activating the heat engine and the rotary
machine driving source, the on-off valve is opened so as to cause
the working medium to flow into the bypass pipe, the heat engine
and the rotary machine driving source are activated, and the on-off
valve of the bypass pipe is closed when it is determined that the
working medium flowing into the expander is evaporated, and wherein
when stopping the heat engine and the rotary machine driving
source, the on-off valve is opened so as to cause the working
medium to flow into the bypass pipe and the driving operation of
the expander is stopped.
15. The method of operating the power generating apparatus
according to claim 1, wherein when the rotary machine driving
source is stopped under the state where the rotary machine driving
source is normally operated, the on-off valve is opened so as to
cause the working medium to flow into the bypass pipe and the
driving operation of the expander is stopped.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a power generating
apparatus capable of using power generated by a heat engine in
combination with power of a driving source provided separately from
the heat engine and an operation method thereof.
[0003] 2. Description of the Related Art
[0004] A heat engine such as a binary cycle engine is configured to
convert heat into power (convert heat energy into motion energy) by
expanding and condensing a working medium of a medium with a low
boiling temperature such as ammonia, pentane, Freon, and
Hydrochlorofluorocarbon through a thermodynamic cycle such as a
Rankine cycle.
[0005] Such a heat engine includes an evaporator which evaporates a
liquid working medium, an expander which expands a steam working
medium, a condenser which condenses a gas working medium used in
the expander into a liquid, and a circulation pump which compresses
and circulates the condensed working medium. Further, a rotational
driving force which is obtained by a rotational driving operation
of the expander is extracted to the outside of a housing
accommodating the expander through a rotational driving shaft and
is used to rotate a rotary machine (for example, a power generator
or the like) connected to a rotational driving shaft.
[0006] As a method of smoothly activating such a heat engine, for
example, there is known a method disclosed in JP 2008-175402 A. In
the related art, the method is used to operate a refrigerating
cycle device, and the refrigerating cycle device includes a
compressor, a radiator, an expander, and an evaporator which are
sequentially connected to one another so as to circulate
refrigerant, and further includes a radiator ability control unit
which controls the ability of the radiator or an evaporator ability
control unit which controls the ability of the evaporator. Here,
the method includes a normal operation step and an activation step
of reducing the ability of the radiator ability control unit or the
evaporator ability control unit for some time from a normal
operation state when activating the compressor.
SUMMARY OF THE INVENTION
[0007] Incidentally, a power generator which is provided in the
heat engine (the refrigerating cycle device) of the related art
generates power by directly receiving a rotational driving force
generated by the expander of the heat engine. That is, the power
generator is a "driven rotary machine". Of course, the power
generator is maintained in a stop state when the rotational driving
force may not be obtained from the expander.
[0008] Meanwhile, there is proposed a method in which a rotational
driving force is generated by a heat engine such as a binary cycle
engine and the obtained rotational driving force is used as
auxiliary power for assisting "power of a driving source provided
separately from the heat engine". For example, a gas compressor
which is driven by a motor is supposed. The gas compressor is an
"active rotary machine" which may be activated and operated
independently, and a system is supposed which supplies the
rotational driving force of the heat engine to such a gas
compressor in order to assist the gas compressor.
[0009] In this case, for example, the following problems may be
caused when activating the system.
[0010] That is, the motor of the gas compressor as the active
rotary machine is activated along with the heat engine. At this
time, since the heat engine is not in a normal operation state, the
rotational power generated from the expander may not be applied as
the auxiliary power to the motor. Conversely, the motor of the gas
compressor rotates the expander. Accordingly, there is a
possibility that the activation of the system may be pretty
delayed. Further, in such a state, a working medium flowing into
the expander is a liquid, and a rotation load of the expander
excessively increases. As a result, the expander may be broken in
the end.
[0011] Such problems are very severe problems, and may not be
solved even by the related art.
[0012] This is because there is a difference in original system
configuration in that the heat engine of the related art is not
used to generate the auxiliary power for assisting the power of the
driving source provided separately from the heat engine. Moreover,
the operation method is used to solve the "problem occurring inside
the heat engine", that is, a "problem in which the load of the
circulation pump increases due to the continuous operation of the
circulation pump (described as the compressor) while the expander
is not driven". Accordingly, the related art may not solve the
problem caused when activating the system including the heat engine
and the active rotary machine connected to the heat engine.
[0013] Therefore, the present invention is made in view of the
above-described problems, and it is an object of the invention to
provide a power generating apparatus capable of using power
generated by a heat engine in combination with power of a driving
source provided separately from the heat engine. Further, it is an
object of the present invention to provide a power generating
apparatus capable of reliably preventing a problem caused when
activating and stopping the apparatus and an operation method
thereof.
[0014] In order to attain the above-described object, the present
invention devises the following technical means.
[0015] According to an aspect of the present invention, there is
provided a power generating apparatus including: a rotary machine
driving source which generates a rotational driving force for a
rotary machine; and a heat engine which drives the rotary machine
in corporation with the rotary machine driving source, wherein the
heat engine includes an expander which expands an evaporated
working medium so as to generate a rotational driving force,
wherein the expander is provided with a bypass pipe which causes a
working medium inlet of the expander to communicate with a working
medium outlet thereof, and wherein the bypass pipe is provided with
an on-off valve which opens and closes the bypass pipe.
[0016] According to the above-described configuration, it is
possible to reliably prevent a problem caused when activating or
stopping the apparatus by temporarily opening the on-off valve when
activating or stopping the rotary machine.
[0017] In the power generating apparatus with the above-described
configuration, the power generating apparatus may further include a
control device which controls an opening and closing operation of
the on-off valve, wherein when activating the rotary machine
driving source and the heat engine, the control device may perform
control which opens the on-off valve so that the working medium
flows into the bypass pipe, activates the rotary machine driving
source, and closes the on-off valve when it is determined that the
working medium flowing into the expander is evaporated.
[0018] In the power generating apparatus with the above-described
configuration, the power generating apparatus may further include a
suction pressure detector which detects a suction pressure of the
expander, wherein the control device may determine that the working
medium flowing into the expander is evaporated when a pressure
value detected by the suction pressure detector becomes a
predetermined pressure value or more.
[0019] Alternatively, in the power generating apparatus with the
above-described configuration, the power generating apparatus may
further include a suction pressure detector which detects a suction
pressure of the expander; and an discharge pressure detector which
detects an discharge pressure of the expander, wherein the control
device may determine that the working medium flowing into the
expander is evaporated when a differential pressure between a
pressure value detected by the suction pressure detector and a
pressure value detected by the discharge pressure detector becomes
a predetermined value or more.
[0020] Alternatively, in the power generating apparatus with the
above-described configuration, the rotary machine may be a gas
compressor, the power generating apparatus may further include a
temperature detector which detects an exhaust gas temperature of
the gas compressor, and the control device may determine that the
working medium flowing into the expander is evaporated when a
temperature value detected by the temperature detector becomes a
predetermined temperature value or more.
[0021] Alternatively, in the power generating apparatus with the
above-described configuration, the control device may include a
time measuring unit which measures an elapse time from the
activation of the rotary machine driving source, and the control
device may determine that the working medium flowing into the
expander is evaporated when the elapse time detected by the time
measuring unit becomes a predetermined time or more.
[0022] Further, in the power generating apparatus with the
above-described configuration, the power generating apparatus may
further include a control device which controls an opening and
closing operation of the on-off valve, wherein when stopping the
rotary machine driving source and the heat engine, the control
device may perform control which opens the on-off valve so that the
working medium flows into the bypass pipe and the driving operation
of the expander is stopped.
[0023] Further, in the power generating apparatus with the
above-described configuration, the power generating apparatus may
further include a control device which controls an opening and
closing operation of the on-off valve, wherein when the rotary
machine driving source is stopped under the state where the rotary
machine driving source and the heat engine are normally operated,
the control device may perform control which opens the on-off valve
so that the working medium flows into the bypass pipe and the
driving operation of the expander is stopped.
[0024] Further, in the power generating apparatus with the
above-described configuration, the rotary machine may be a
compressor which compresses a gas supplied thereto in a high
pressure state and the rotary machine driving source is a motor,
and heat of a high-pressure gas produced by the compressor may be
used as a heat source for a working medium in an evaporator of the
heat engine.
[0025] Further, in the power generating apparatus with the
above-described configuration, the rotary machine driving source
may be a second expander which generates power by expanding a
heating medium as steam, and an evaporator of the heat engine may
heat and evaporate the working medium by the heating medium
expanded by the second expander.
[0026] In this aspect, since the heating medium to be introduced
into the evaporator is expanded by the second expander, the
pressure of the heating medium introduced into the evaporator
decreases compared to the related art. For this reason, the stress
strain generated in the member constituting the evaporator may be
reduced, and hence the burden on the evaporator may be reduced.
Moreover, since the second expander is connected to the rotary
shaft provided in the rotor portion of the rotary machine, the
energy of the heating medium may be extracted as the energy of
driving the rotor portion in the second expander. Accordingly,
since the energy of the heating medium may be used without waste,
the performance of the rotary machine driving system may be
improved. That is, the pressure of the heating medium is used in
the second expander, and the temperature of the heating medium of
which the pressure decreases is used in the evaporator.
Accordingly, the energy of the heating medium may be efficiently
used compared to the related art.
[0027] Further, in the power generating apparatus with the
above-described configuration, the power generating apparatus may
further include: a first shaft portion which is connected to a
rotary shaft of the heat engine; a second shaft portion which is
connected to a rotary shaft of the second expander; and a coupling
portion which couples the first shaft portion and the second shaft
portion to each other so that a driving force is transmitted
through the coupled shaft portions, wherein the coupling portion
may be configured as a speed increasing and decreasing mechanism
which is provided between the first shaft portion and the second
shaft portion so as to change a rotation speed.
[0028] Further, in the power generating apparatus with the
above-described configuration, water used in a condenser of the
heat engine or water condensed from the steam in the evaporator of
the heat engine may be supplied as lubricant to a bearing of the
rotary shaft of the second expander.
[0029] Further, in the power generating apparatus with the
above-described configuration, the power generating apparatus may
further include: a first shaft portion which is connected to a
rotary shaft of the heat engine; a second shaft portion which is
connected to a rotary shaft of the rotary machine driving source;
and a coupling portion which couples the first shaft portion and
the second shaft portion to each other so that a driving force is
transmitted through the coupled shaft portions, wherein at least
one of the first shaft portion and the second shaft portion may be
accommodated inside a hermetic body, and wherein the coupling
portion may be configured as a magnetic coupling which magnetically
couples the first shaft portion and the second shaft portion to
each other.
[0030] Further, according to another aspect of the present
invention, there is provided a method of operating the power
generating apparatus with the above-described configuration,
wherein when activating the heat engine and the rotary machine
driving source, the on-off valve is opened so as to cause the
working medium to flow into the bypass pipe, the heat engine and
the rotary machine driving source are activated, and the on-off
valve of the bypass pipe is closed when it is determined that the
working medium flowing into the expander is evaporated, and wherein
when stopping the heat engine and the rotary machine driving
source, the on-off valve is opened so as to cause the working
medium to flow into the bypass pipe and the driving operation of
the expander is stopped.
[0031] Alternatively, in the method of operating the power
generating apparatus with the above-described configuration, when
the rotary machine driving source is stopped under the state where
the rotary machine driving source is normally operated, the on-off
valve is opened so as to cause the working medium to flow into the
bypass pipe and the driving operation of the expander is
stopped.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a diagram schematically illustrating a
configuration of a power generating apparatus according to a first
embodiment of the present invention.
[0033] FIG. 2 is a perspective view illustrating a magnetic
coupling provided in the power generating apparatus of the first
embodiment.
[0034] FIG. 3 is a flowchart illustrating a method of operating the
power generating apparatus of the first embodiment.
[0035] FIG. 4 is a diagram schematically illustrating a
configuration of a power generating apparatus according to a second
embodiment of the present invention.
[0036] FIG. 5 is a diagram schematically illustrating a
configuration of a power generating apparatus according to a third
embodiment of the present invention.
[0037] FIG. 6 is a diagram schematically illustrating a
configuration of a power generating apparatus of a fourth
embodiment of the present invention.
[0038] FIG. 7 is a diagram schematically illustrating a
configuration of a power generating apparatus of a fifth embodiment
of the present invention.
[0039] FIG. 8 is a diagram schematically illustrating a
configuration of a power generating apparatus of a sixth embodiment
of the present invention.
[0040] FIG. 9 is a diagram schematically illustrating a
configuration of a power generating apparatus of a seventh
embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0041] Hereinafter, a first embodiment of a power generating
apparatus 100 according to the present invention will be described
by referring to the drawings.
[0042] As illustrated in FIG. 1, the power generating apparatus 100
of the first embodiment includes an auxiliary power generating
apparatus 1, a motor 53 which drives a rotary machine 11, and two
power generating sources. The auxiliary power generating apparatus
1 includes a heat engine 4 which includes an expander 3 with a
driving portion 2 (a screw rotor 2 in this embodiment) rotationally
driven by the expansion of steam of a working medium T and a power
transmission shaft 6 which extracts a rotational driving force
generated by the expander 3 to the outside of a housing 5
accommodating the expander 3.
[0043] The housing 5 accommodates the driving portion 2 of the
expander 3 in the inner portion surrounded by a partition wall 7.
The power transmission shaft 6 is divided by a partition wall 7
into a driving shaft 8 positioned inside the housing 5 and a driven
shaft 9 positioned outside the housing 5. Further, the divided
power transmission shafts 6, that is, the driving shaft 8 and the
driven shaft 9 are provided with a magnetic coupling 10 which
transmits the rotational driving force of the expander 3 to the
outside of the housing 5.
[0044] In this way, the auxiliary power generating apparatus 1
includes the magnetic coupling 10 and the power transmission shaft
6 with the driving shaft 8 and the driven shaft 9. Then, the
auxiliary power generating apparatus 1 transmits the rotational
driving force to the outside of the housing 5 by the power
transmission shaft 6 and transmits the rotational driving force to
the rotary machine 11 provided separately from the heat engine 4 so
that the rotational driving force is used as auxiliary power of the
rotary machine 11.
[0045] The present invention relates to a technique capable of
preventing a problem caused when activating or stopping the
auxiliary power generating apparatus 1. However, the auxiliary
power generating apparatus 1 and the rotary machine 11 assisted by
the auxiliary power generating apparatus 1 will be described before
the description of the technique of the present invention.
[0046] First, the rotary machine 11 as a subject to which the
auxiliary power is supplied from the power generating apparatus 1
will be described in detail.
[0047] As the rotary machine 11 of the first embodiment, a "gas
compressor" which compresses a supplied gas V in a high pressure
state is employed.
[0048] As illustrated in FIG. 1, a gas compressor 50 includes a
plurality of compressors (a first-stage compressor 51 and a
second-stage compressor 52) which are connected to each other in
series in the axial direction and a motor 53 which drives the
plurality of compressors, and is configured as an oil-free
multi-stage gas compressor which does not use lubricating oil. The
motor 53 which generates a driving force is an electric motor. In
such a gas compressor 50, the gas V which is introduced from the
outside is adiabatically compressed by the first-stage compressor
so as to become the high-pressure gas V, and is sent to the
second-stage compressor. The sent high-pressure gas V is further
adiabatically compressed by the second-stage compressor so as to
become the high-pressure gas V. At this time, the produced gas V
increases in temperature so that the gas has much heat. The
high-pressure gas V which is produced in this way is cooled to a
desired temperature according to the use purpose by a cooling
device such as a cooler 54.
[0049] The above-described gas compressor 50 (the rotary machine
11) is provided for a user as one component and includes the motor
53. Accordingly, the gas compressor may be operated as a single
unit (a main rotary machine). The auxiliary power generating
apparatus 1 of this embodiment is additionally attached to the gas
compressor 50 and assists the power of the gas compressor 50.
[0050] Meanwhile, the heat engine 4 which is provided in the
auxiliary power generating apparatus 1 of the first embodiment will
be described in detail.
[0051] A binary cycle engine is exemplified as the heat engine 4
provided in the auxiliary power generating apparatus 1 of the first
embodiment.
[0052] As illustrated in FIG. 1, the binary cycle engine 4 is
provided on a close-loop-shaped circulation pipe obtained by
connecting an evaporator 13 which evaporates the liquid working
medium T, the expander 3 which expands the steam of the working
medium T evaporated by the evaporator 13 so as to rotationally
drive the driving portion 2 (for example, the screw rotor 2 to be
described later), a condenser 12 which condenses the steam of the
working medium T expanded by the expander 3 so as to be changed
into the liquid working medium T, and a medium circulating pump 14
which circulates the working medium T by pressure-feeding the
liquid working medium T condensed by the condenser 12 to the
evaporator 13.
[0053] The expander 3 includes the screw rotor 2 (the driving
portion 2) which is rotationally driven by using a difference in
pressure between the non-expanded steam and the expanded steam. The
screw rotor 2 is rotatable about the driving shaft 8, and may
transmit the generated rotational driving force to the magnetic
coupling 10 connected to the driving shaft 8 through the driving
shaft 8.
[0054] The housing 5 (the partition wall 7) is provided in the
periphery of the screw rotor (the driving portion) 2 of the
expander 3, and the inside and the outside may be air-tightly
isolated by the housing 5. The housing 5 which is used for the
air-tight isolation stores the working medium T as a medium with a
low boiling temperature that is used in the binary cycle engine 4
along with the screw rotor 2.
[0055] A power transmission unit which transmits the rotational
driving force generated by the screw rotor 2 of the expander 3 to
the gas compressor 50 is disposed between the expander 3 and the
gas compressor 50.
[0056] The power transmission unit includes the power transmission
shaft 6 which is divided by the partition wall 7 into the driving
shaft 8 and the driven shaft 9 and the magnetic coupling 10 (see
FIG. 2) which magnetically couples both shafts divided by the
partition wall 7 to the inside and the outside of the housing 5,
and includes a power transmission path 15 with the power
transmission shaft 6 and the magnetic coupling 10.
[0057] Then, the rotational driving force which is extracted
through the magnetic coupling 10 is transmitted to the gas
compressor 50 which is provided separately from the binary cycle
engine 4 and is driven by the power of the driving source 16, so
that the rotational driving force is used as the auxiliary power
for driving the gas compressor 50.
[0058] Further, the power transmission path 15 to which the
rotational driving force extracted through the magnetic coupling 10
is provided with a speed changer 17 which changes the rotation
speed of the power transmission shaft 6 and transmits the auxiliary
power to the downstream side and a clutch mechanism 18 which
controls the auxiliary power transmission state to the gas
compressor 50.
[0059] Next, the power transmission shaft 6 and the magnetic
coupling 10 constituting the auxiliary power generating apparatus 1
will be described.
[0060] As illustrated in FIG. 1, the power transmission shaft 6 is
divided by the partition wall 7 of the housing 5 into the driving
shaft 8 and the driven shaft 9. One driving shaft 8 of the divided
power transmission shafts 6 is a rotary shaft which is disposed
along the rotation axis of the screw rotor 2 of the expander 3. One
end (the right side of FIG. 1) of the driving shaft 8 is connected
to the screw rotor 2 as the driving portion 2 of the expander 3,
and the other end (the left side of FIG. 1) thereof extends to the
vicinity of the partition wall 7. The front end of the other end
side is provided with an outer cylinder body 20 of the magnetic
coupling 10 attached to a driving side magnet.
[0061] Meanwhile, one driven shaft 9 of the divided power
transmission shafts 6 is a shaft which is rotatably disposed along
the coaxial direction with the driving shaft 8. One end (the right
side of FIG. 1) of the driven shaft 9 extends toward the expander
3, where one end thereof is provided with an inner insertion body
22 attached to a driven side magnet and the other end (the left
side of FIG. 1) thereof is connected to the speed changer 17 to be
described later.
[0062] As illustrated in FIGS. 1 and 2, the magnetic coupling 10
includes the outer cylinder body 20 which is provided in the
driving shaft 8 and the inner insertion body 22 which is provided
in the driven shaft 9.
[0063] The outer cylinder body 20 is a bottomed cylindrical member
that is opened to the side of the gas compressor 50 (the opposite
side to the screw rotor 2), and is formed of a non-magnetic
material. The driving shaft 8 is coaxially connected to the outer
cylinder body 20, and the cylindrical portion is provided with two
driving side magnets which are disposed in the circumferential
direction so as to face each other.
[0064] The inner insertion body 22 is a columnar body, and is
formed of a non-magnetic material as in the outer cylinder body 20.
The inner insertion body 22 is loosely insertable into the outer
cylinder body 20, and driven side magnets 26 corresponding to the
number the driving side magnets 25 are attached to the outer
peripheral surface of the inner insertion body 22 (the outer
peripheral surface of the portion inserted into the outer cylinder
body 20). Further, the number of the driving side magnets 25 and
the number of the driven side magnets 26 of the magnetic coupling
are not limited to two, and may be two or more.
[0065] The driving side magnets 25 and the driven side magnets 26
are disposed so that different magnetic poles face each other, and
a magnetic attracting force is generated between both magnets 25
and 26 so as to permeate the partition wall 7. Accordingly, the
rotational driving force of the driving shaft 8 may be transmitted
to the driven shaft 9.
[0066] Incidentally, the configuration of the auxiliary power
generating apparatus 1 of the present invention has been
sequentially described, and then the evaporator 13 provided in the
binary cycle engine 4 will be described.
[0067] The evaporator 13 which is provided in the binary cycle
engine 4 of the first embodiment is provided as two or more
evaporators (a first evaporator 56 and a second evaporator 57 in
FIG. 1) at the downstream side of the medium circulating pump 14 so
as to use the heat generated by the gas compressor 50 as a heat
source which evaporates the working medium T.
[0068] The first evaporator 56 and the second evaporator 57 are
disposed in parallel on a circulation pipe 55. The inlets of the
first evaporator 56 and the second evaporator 57 are respectively
connected with pipes which are branched in parallel from the
circulation pipe 55 connected to the downstream side of the medium
circulating pump 14. The pipes which extend from the outlets of the
first evaporator 56 and the second evaporator 57 are respectively
connected to the circulation pipe 55 at the upstream side of the
expander 3.
[0069] The high-pressure gas V which is adiabatically compressed by
the first-stage compressor 51 of the gas compressor 50 flows into
the first evaporator 56 so that the high-pressure gas V exchanges
heat with the working medium T. The high-pressure gas V which is
subjected to the heat exchange operation is sent to the
second-stage compressor 52.
[0070] The high-pressure gas V which is adiabatically compressed by
the second-stage compressor 52 flows into the second evaporator 57
so that the high-pressure gas V exchanges heat with the working
medium T. The high-pressure gas V which is subjected to the heat
exchange operation is sent to the cooler 54 (the cooling device)
and is cooled to a desired temperature in accordance with the use
purpose.
[0071] The gas working medium T which is provided in this way is
sent to the expander 3 through the circulation pipe 55 connected to
the outlets of the first evaporator 56 and the second evaporator
57.
[0072] Incidentally, a bypass pipe 63 (bypass passage) is disposed
between the expander 3 and the circulation pipe 55 connected to the
outlets of the first evaporator 56 and the second evaporator
57.
[0073] The bypass pipe 63 is disposed so as to connect the inlet of
the expander 3 to the outlet of the expander 3. The bypass pipe 63
is provided with an on-off valve 64 which changes the circulation
state inside the bypass pipe 63. The on-off valve 64 is turned on
or off by the operation state of the auxiliary power generating
apparatus 1 so as to permit the circulation of the working medium T
or interrupt the circulation of the working medium T.
[0074] The problem which is caused by activating or stopping the
auxiliary power generating apparatus 1 may be prevented by using
the bypass pipe 63, and the detailed description thereof will made
below.
[0075] Hereinafter, the operation manner of the auxiliary power
generating apparatus 1 according to the first embodiment, that is,
the operation in a normal operation state will be described by
referring to the drawings.
[0076] As illustrated in FIG. 1, in the first evaporator 56, the
steam working medium T is produced by evaporating the liquid
working medium T using (exchanging) the heat of the high-pressure
gas V produced by the first-stage compressor 51. Further, in the
second evaporator 57, the steam working medium T is produced by
evaporating the liquid working medium T using (exchanging) the heat
of the high-pressure gas V produced by the second-stage compressor
52 as in the first evaporator 56. The steam working medium T which
is produced in this way is sent to the expander 3 through the
circulation pipe 55 connected to the outlets of the first
evaporator 56 and the second evaporator 57.
[0077] In the expander 3, the steam of the working medium T
produced by the first evaporator 56 and the second evaporator 57 is
expanded, and the driving portion 2 is rotationally driven by using
a difference in pressure between the non-expanded working medium T
and the expanded working medium T.
[0078] The steam of the low-pressure working medium T used in the
expander 3 is sent to the condenser 12 through the outlet-side
circulation pipe 55 of the expander 3. In the condenser 12, the
steam of the working medium T sent from the expander 3 exchanges
heat with the cooling water W so as to be condensed into the liquid
working medium T.
[0079] The working medium T which becomes a liquid by the condenser
is sent to the medium circulating pump 14. The liquid working
medium T is boosted by the medium circulating pump 14, and is
pressure-fed to both evaporators 56 and 57 again through the
circulation pipe 55.
[0080] Meanwhile, the rotational driving force which is generated
by the expander 3 and the rotational driving force which is
extracted to the outside of the housing 5 through the magnetic
coupling 10 are first transmitted to the speed changer 17 through
the driven shaft 9 connected to the magnetic coupling 10.
[0081] After the rotation speed is changed to the rotation speed
best suitable for driving the gas compressor 50 by the speed
changer 17, the rotational driving force obtained after the speed
changing operation is transmitted to the motor 53 of the gas
compressor 50 through the clutch mechanism 18 so as to assist the
power thereof.
[0082] Incidentally, the following problems are supposed when
operating the auxiliary power generating apparatus 1.
[0083] For example, there is a concern that the following situation
may occur when starting (activating) the gas compressor 50 again by
supplying power to the stopped gas compressor 50.
[0084] When power is supplied to the stopped gas compressor 50 so
that the motor 53 starts to rotate, the motor 53 drives the
compressors 51 and 52. At this time, in the auxiliary power
generating apparatus 1, that is, the binary cycle, the heat for
driving the expander 3 is not supplied to the evaporator 13, and
the liquid working medium T circulates through the circulation pipe
55. The liquid working medium T may not drive the expander 3, and
the motor 53 of the gas compressor 50 rotates the expander 3
(serving as a load) into which the liquid working medium T flows.
That is, since the motor 53 of the gas compressor 50 tries to
rotate both the compressors 51 and 52 and the expander 3, a large
load is applied to the motor 53, and hence the start of the entire
apparatus is delayed.
[0085] However, in this embodiment, this problem is prevented by
employing the operation method illustrated in FIG. 3.
[0086] That is, in the auxiliary power generating apparatus 1
according to the first embodiment, the on-off valve 64 is opened
when activating the gas compressor 50 (S101, S102 of FIG. 3). In
this way, since the working medium may circulate through the bypass
pipe 63, the liquid working medium T may be branched at the inlet
side of the expander 3, so that the liquid working medium
substantially does not flow into the expander 3. Then, the expander
3 may idly rotate, and hence the above-described problem may be
prevented.
[0087] Subsequently, the gas compressor 50 is normally operated so
that the high-pressure gas V is discharged. The heat of the
high-pressure gas V evaporates the working medium T through the
evaporator 13. When the suction pressure of the expander 3, the
differential pressure between the suction side and the discharge
side of the expander 3, or the exhaust heat temperature of the gas
compressor 50 is measured and it is determined that the measurement
value is a predetermined value or more (S103 of FIG. 3), the on-off
valve 64 of the bypass pipe 63 is closed (S104 of FIG. 3). All
evaporated working medium flows into the expander 3, so that the
auxiliary power generating apparatus 1 is normally operated.
Furthermore, in S103, it is determined whether the operation time
of the gas compressor 50 becomes a predetermined time or more. When
the operation time becomes a predetermined time or more, the
routine may proceed to S104. Here, the predetermined value and the
predetermined time are set as a value which may be used to check
the evaporation state of the working medium flowing into the
expander.
[0088] As illustrated in FIG. 1, as the apparatus configuration for
realizing the above-described operation method, the power
generating apparatus 100 according to the first embodiment includes
a control device 70. Further, the suction pressure detector Ps is
provided for the case where the suction pressure of the expander 3
is used in S103, the suction pressure detector Ps and the discharge
pressure detector Pd are provided for the case where the
differential pressure between the suction side and the discharge
side of the expander 3 is used in S103, and the temperature
detector T is provided for the case where the exhaust heat
temperature of the gas compressor 50 is used in S103. In the
embodiment of FIG. 1, the discharge gas temperature of the
first-stage compressor 51 of the gas compressor 50 is measured, but
instead of this, the discharge gas temperature of the second-stage
compressor 52 may be measured.
[0089] In a case of the operation in which the on-off valve 64 is
automatically opened when activating the gas compressor 50 and the
on-off valve 64 is automatically closed after a predetermined time,
the control device 70 includes a time measuring unit 71 which
measures the elapse time from the activation of the gas compressor
50.
[0090] As the determination in S103, only one of the four
determination methods may be used. Alternatively, a control may be
performed in which the on-off valve 64 is opened when the
determination method used in combination with the plurality of
determination methods becomes the condition of opening the on-off
valve 64.
[0091] The opening and closing operation of the on-off valve 64 may
be performed by the manual operation of the operator without using
the control device 70.
[0092] Next, the operation of the auxiliary power generating
apparatus 1 when stopping the gas compressor 50 will be described.
Immediately after stopping the gas compressor 50, the steam working
medium T continuously flows into the expander 3 of the auxiliary
power generating apparatus 1 through the circulation pipe 55. In
this state, the expander 3 becomes an overload state since the
expander needs to drive the motor 53 in addition to the compressors
51 and 52 of the gas compressor 50. When an excessive overload is
applied to the expander, the magnetic coupling 10 which is present
between the expander 3 and the motor 53 may not transmit power and
idly rotate, and hence there is a concern that the expander 3 may
excessively rotate in a non-load state.
[0093] However, in such a stop case, the auxiliary power generating
apparatus 1 according to the first embodiment opens the on-off
valve 64 (S201 of FIG. 3) so that the working medium may pass
through the bypass pipe 63. Accordingly, the inflow of the working
medium into the expander 3 is suppressed. As a result, the driving
operation of the expander 3 is stopped. Then, the driving operation
of the compressors 51 and 52 is stopped along with the stop of the
driving operation of the motor 53 of the gas compressor 50 (S202 of
FIG. 3). Then, the above-described problem is reliably prevented.
Furthermore, the operation of opening the on-off valve 64 and the
operation of stopping the driving operation of the motor 53 may be
performed at the same time. The same applies to the operation of
the auxiliary power generating apparatus 1 in case of power outage
below.
[0094] In the gas compressor 50, there is a case in which power is
not supplied to the gas compressor in a normal operation state due
to abrupt power outage or the like. Since the steam working medium
T continuously flows into the expander 3 of the auxiliary power
generating apparatus 1 through the circulation pipe 55, the
expander 3 drives the motor 53 and the compressors 51 and 52 of the
gas compressor 50 which is stopped due to the power outage, and
hence becomes an overload state. When an excessive overload is
applied to the expander, the magnetic coupling 10 which is present
between the expander 3 and the motor 53 may not transmit power and
idly rotates. Conversely, there is a concern that the expander 3
may excessively rotate in a non-load state.
[0095] However, in such a power outage case, the auxiliary power
generating apparatus 1 according to the first embodiment opens the
on-off valve 64 (S201 of FIG. 3) so that the working medium may
pass through the bypass pipe 63. Thus, the inflow of the working
medium into the expander 3 is suppressed and hence the driving
operation of the expander 3 is stopped. Then, the driving operation
of the compressors 51 and 52 is stopped along with the stop of the
driving of the motor 53 of the gas compressor 50 (S202 of FIG. 3).
Then, the above-described problem is reliably prevented.
[0096] When opening and closing the on-off valve 64, the opening
and closing operation may be manually performed by the operator,
but a configuration may be employed in which the on-off valve 64
automatically detects power outage and is automatically opened when
detecting the power outage.
Second Embodiment
[0097] Next, a second embodiment of the power generating apparatus
100 of the present invention will be described by referring to the
drawings.
[0098] As illustrated in FIG. 4, the configuration of the auxiliary
power generating apparatus 1 according to the second embodiment is
different from the configuration of the first embodiment as
below.
[0099] That is, the binary cycle engine 4 of the second embodiment
has a difference in that the heat source for evaporating the
working medium T is supplied from the outside. In other words, the
heat generated by the rotary machine 11 is not used (collected) as
the heat source for evaporating the working medium T. In this way,
the auxiliary power generating apparatus 1 of the second embodiment
includes the binary cycle engine 4 with a simple configuration.
Furthermore, various rotary machines such as a motor or a
compressor may be used in the rotary machine 11.
[0100] However, the second embodiment is substantially the same as
the first embodiment in that the bypass pipe 63 causing the inlet
and the outlet of the expander 3 to communicate with each other is
provided and the bypass pipe 63 is provided with the on-off valve
64 for enabling and disabling the circulation of the working medium
T.
[0101] Even in the auxiliary power generating apparatus 1, that is,
in the binary cycle engine 4, the problem caused when activating or
stopping the apparatus mentioned in the first embodiment may
occur.
[0102] Even in this case, it is possible to reliably prevent the
problem caused when activating and stopping the apparatus even in
the apparatus of the second embodiment that uses the bypass pipe 63
connecting the inlet of the expander 3 and the outlet of the
expander 3 to each other and performs an operation based on the
flowchart illustrated in FIG. 3.
[0103] Furthermore, since the other configurations and the supposed
operation and effect in the second embodiment are substantially the
same as those of the first embodiment, the description thereof will
not be repeated. Furthermore, in FIG. 4, the control device and
various detectors are not illustrated.
Modified Example
[0104] In the apparatus 100 of the first embodiment and the second
embodiment, the configuration may be modified as below.
[0105] For example, in the first embodiment, the heat of the
high-pressure gas V produced by the gas compressor 50 is used as
the heat source of the binary cycle engine 4. However, when a water
cooling type engine (internal combustion engine) is employed in the
rotary machine 11, the cooling water for cooling the engine may be
used as the heat source of the binary cycle engine 4.
[0106] Further, even when an air clutch is employed as the clutch
mechanism 18 disposed in the auxiliary power generating apparatus
1, a problem caused in the case of power outage or activation may
be prevented.
[0107] That is, a configuration may be employed in which the air
clutch is used as the clutch mechanism 18 and a part of the gas V
compressed by the gas compressor 50 is guided to the air
clutch.
[0108] For example, when the gas compressor 50 which is normally
operated is stopped due to the abrupt power outage or the like, the
high-pressure gas V is not supplied (only the low-pressure gas V
exists), and the air clutch is not operated. Accordingly, the
expander 3 of the auxiliary power generating apparatus 1 is not
automatically interlocked with the motor 53 of the gas compressor
50. For this reason, it is possible to reliably prevent the problem
caused in the case of power outage. Since the high-pressure gas V
is supplied during the normal operation of the gas compressor 50,
the air clutch is operated.
[0109] Such an operation of the air clutch occurs in the same way
even when starting the gas compressor 50. That is, in the
activation state, the high-pressure gas V is not supplied from the
gas compressor 50 (only the low-pressure gas V exists), and the air
clutch is not operated. Accordingly, the expander 3 of the
auxiliary power generating apparatus 1 is not automatically
interlocked with the motor 53 of the gas compressor 50 only for
some time. For this reason, it is possible to reliably prevent the
problem caused when activating the apparatus.
Third Embodiment
[0110] FIG. 5 illustrates a configuration of a power generating
apparatus of a third embodiment. Specifically, the power generating
apparatus includes a circulation circuit 110 that is a binary cycle
engine through which the working medium circulates, a power
generator 120 as a rotary machine, a heating medium circuit 130,
and a control unit 150 which performs various controls.
Furthermore, a working medium (for example, HFC245fa) having a
boiling temperature lower than that of water circulates through the
circulation circuit 110.
[0111] The circulation circuit 110 is a closed circuit which is
obtained by serially connecting an evaporator 111 which evaporates
a working medium, a first expander 113 which expands a gas working
medium, a condenser 114 which condenses a working medium expanded
by the first expander 113, and a working medium pump 115 which
sends the working medium condensed by the condenser 114 to the
evaporator 111.
[0112] The evaporator 111 is used to evaporate the liquid working
medium. The evaporator 111 includes a working medium passage 111a
through which the working medium flows and a heating medium passage
111b through which the heating medium flows. The heating medium
passage 111b is connected to the heating medium circuit 130 as
described below, so that the heating medium flows therethrough. The
working medium which flows through the working medium passage 111a
evaporates by the heat exchange with the heating medium flowing
through the heating medium passage 111b.
[0113] The first expander 113 is provided at the downstream side of
the evaporator 111 in the circulation circuit 110, and expands the
working medium evaporated by the evaporator 111, so that motion
energy is extracted from the working medium. In this embodiment, a
screw expander is used as the first expander 113. In the screw
expander, a pair of male and female screw rotors 113b is
accommodated in a rotor chamber (not illustrated) formed inside a
casing 113a of the first expander 113. In the screw expander, the
screw rotor 113b is rotated by the expanding force of the working
medium supplied from the suction port formed in the casing 113a to
the rotor chamber. Then, the working medium of which the pressure
decreases is discharged from the outlet formed in the casing 113a
due to the expansion inside the rotor chamber. Furthermore, the
first expander 113 is not limited to the screw expander, but may be
other expanders such as a turbine expander.
[0114] The condenser 114 condenses a gas working medium discharged
from the first expander 113 so as to be changed into a liquid
working medium. The condenser 114 includes a working medium passage
114a through which a gas working medium flows and a cooling medium
passage 114b through which a cooling medium flows. The cooling
medium passage 114b is connected to a cooling medium circuit 117,
and the cooling medium supplied from the outside flows through the
cooling medium circuit 117. As the cooling medium, for example,
cooling water cooled by a cooling tower may be exemplified. The
working medium which flows through the working medium passage 114a
is condensed by the heat exchange with the cooling medium flowing
through the cooling medium passage 114b.
[0115] The working medium pump 115 is used to circulate the working
medium inside the circulation circuit 110, and is provided at the
downstream side of the condenser 114 (between the evaporator 111
and the condenser 114) in the circulation circuit 110. The working
medium pump 115 pressurizes the liquid working medium condensed by
the condenser 114 to a predetermined pressure and sends the liquid
working medium to the evaporator 111. As the working medium pump
115, a centrifugal pump which includes an impeller as a rotor or a
gear pump which includes a rotor as a pair of gears is used. The
working medium pump 115 may be driven at an arbitrary rotation
speed.
[0116] The power generator 120 includes a rotor portion 120a, and
the rotor portion 120a is provided in an intermediate portion of a
rotary shaft 123 connected to one screw rotor 113b of the first
expander. When the screw rotor 113b is driven by the expansion of
the working medium inside the first expander 113, the rotary shaft
123 rotates. Accordingly, the rotor portion 120a rotates. Since the
rotor portion 120a rotates along with the rotation of the rotary
shaft 123, the power generator 120 generates power. In this
embodiment, an IPM power generator (permanent magnet synchronized
power generator) is used as the power generator 120. The power
generator 120 may adjust the rotation speed by an inverter (not
illustrated). The control unit 150 outputs a rotation speed
adjusting signal to an inverter (not illustrated) so as to adjust
the rotation speed of the power generator 120 so that the power
generation efficiency of the power generator 120 is improved as
much as possible. Furthermore, the power generator 120 is not
limited to the IPM power generator, but may be other power
generators, for example, an induction power generator and the
like.
[0117] The circulation circuit 110 is provided with a bypass
passage 125. The bypass passage 125 is provided with a bypass valve
125a which is configured as an on-off valve, and the bypass passage
125 opens the bypass valve 125a so that the working medium flows so
as to bypass the first expander 113 in the circulation circuit 110.
One end of the bypass passage 125 is connected to a pipe between
the evaporator 111 and the first expander 113 in the circulation
circuit 110, and the other end of the bypass passage 125 is
connected to a pipe between the first expander 113 and the
condenser 114 in the circulation circuit 110.
[0118] The heating medium circuit 130 may be connected to an
external medium passage 135, and a heating medium is introduced
from the external medium passage 135 into the heating medium
circuit 130. One end (upstream end) of the heating medium circuit
130 is provided with a second expander 140. The heating medium
which is supplied through the external medium passage 135 is
introduced into the second expander 140, and the second expander
140 extracts motion energy from the heating medium by expanding the
heating medium. In this embodiment, the screw expander is used as
the second expander 140, but other expanders such as a turbine
expander may be used.
[0119] As the heating medium supplied to the heating medium circuit
130, for example, steam sampled from a well (steam well), steam
discharged from a factory or the like, steam produced by a solar
energy collector using solar heat as a heat source, steam produced
by exhaust heat of an engine, a compressor, and the like, and steam
produced from a boiler using a biomass or a fossil fuel as a heat
source may be exemplified. The heating medium which is introduced
into the second expander 140 is, for example, 120.degree. C. to
250.degree. C.
[0120] The second expander 140 is connected to the rotary shaft
123. That is, the rotary shaft 123 is connected to one screw rotor
140a of the second expander 140. When the screw rotor 140a is
driven by the expansion of the heating medium inside the second
expander 140, the rotary shaft 123 rotates.
[0121] The heating medium passage 111b of the evaporator 111 is
connected to the heating medium circuit 130. Accordingly, the
heating medium which is expanded by the second expander 140 flows
through the heating medium passage 111b of the evaporator 111.
[0122] The circulation circuit 110 is provided with an entering
side pressure sensor Ps and a back pressure sensor Pd. The entering
side pressure sensor Ps is provided in a pipe between the
evaporator 111 and the first expander 113 among the pipe
constituting the circulation circuit 110. The back pressure sensor
Pd is provided in a pipe between the first expander 113 and the
condenser 114 among the pipe constituting the circulation circuit
110.
[0123] The control unit 150 includes a ROM, a RAM, a CPU, and the
like, and exhibits a predetermined function by executing a program
stored in the ROM. The function of the control unit 150 includes
the pump control unit 151 and the opening and closing control unit
152.
[0124] The pump control unit 151 controls the rotation speed of the
working medium pump 115 Since the rotation speed of the working
medium pump 115 is controlled by an inverter (not illustrated), the
pump control unit 151 performs the rotation speed control of the
working medium pump 115 by sending a control signal to the
inverter.
[0125] The opening and closing control unit 152 performs control
which opens the bypass valve 125a when the second expander 140 is
driven at a timing earlier than the driving of the first expander
113 by the working medium. For example, in the activation state,
the driving of the second expander 140 by the heating medium is
started at a timing earlier than the driving of the first expander
113 by the working medium. That is, in the evaporator 111, the
working medium flowing through the working medium passage 111a is
heated and evaporated by the heating medium flowing through the
heating medium passage 111b. For this reason, the steam working
medium may not be introduced into the first expander 113 until a
predetermined time is elapsed from the state where the heating
medium flows through the heating medium circuit 130. At this time,
the power generator 120 and the first expander 113 are driven by
the second expander 140 until the undamped steam starts to be
introduced into the first expander 113. For this reason, when the
liquid working medium is introduced into the first expander 113,
the load of the second expander 140 increases. Therefore, the screw
rotor 113b of the first expander 113 may idly rotate by opening the
bypass valve 125a in the activation state.
[0126] When the opening and closing control unit 152 receives the
activation instruction of the working medium pump 115, the opening
and closing control unit performs control which opens the bypass
valve 125a. Subsequently, when a difference in pressure between the
detection value of the entering side pressure sensor Ps and the
detection value of the back pressure sensor Pd reaches a
predetermined threshold value, the opening and closing control unit
performs control which closes the bypass valve 125a. The threshold
value of the difference in pressure is set to a pressure which may
be determined as a state where the working medium is sufficiently
evaporated by the evaporator 111 so that the first expander 113 may
be driven.
[0127] Furthermore, the opening and closing control of the bypass
valve 125a is not limited thereto. For example, a configuration may
be employed in which the back pressure sensor Pd is not provided,
the opening and closing control unit performs control which opens
the bypass valve 125a when the opening and closing control unit 152
receives the activation instruction of the working medium pump 115,
and the opening and closing control unit performs control which
closes the bypass valve 125a when the detection value of the
entering side pressure sensor Ps reaches a predetermined threshold
value. Further, a configuration may be employed in which pressure
sensors (a second entering side pressure sensor and a second back
pressure sensor) are respectively provided at the inlet side and
the outlet side of the second expander 140, the bypass valve 125a
is opened when a difference in pressure obtained from the second
entering side pressure sensor and the second back pressure sensor
becomes equal to or larger than a predetermined threshold value and
a difference in pressure obtained from the entering side pressure
sensor Ps and the back pressure sensor Pd becomes smaller than a
predetermined threshold value, and the bypass valve 125a is closed
when a difference in pressure obtained from the entering side
pressure sensor Ps and the back pressure sensor Pd becomes equal to
or larger than a predetermined threshold value. Further, a
configuration may be employed in which the entering side pressure
sensor Ps and the back pressure sensor Pd are not provided and the
bypass valve 125a is closed when a predetermined time is elapsed
from the receiving of the activation instruction of the working
medium pump 115.
[0128] Subsequently, a method of controlling an operation when
activating the power generating apparatus according to this
embodiment will be described. The basic flow is the same as the
flow of the first embodiment illustrated in FIG. 3. However, in
this embodiment, a method of using a differential pressure between
the suction side and the discharge side of the expander is
employed.
[0129] In a case of activating the power generating apparatus,
first, the control unit 150 receives an activation instruction.
When the control unit 150 receives the activation instruction,
control is performed which opens the bypass valve 125a. At this
time, the heating medium is introduced from the external medium
passage 135 into the heating medium circuit 130. The heating medium
is introduced into the second expander 140 and is expanded therein,
so that the second expander 140 is driven. By the driving of the
second expander 140, the rotor portion 120a of the power generator
120 rotates, so that the power generator 120 starts to generate
power. The heating medium of which the pressure is decreased by the
expansion of the second expander 140 flows into the heating medium
passage 111b of the evaporator 111.
[0130] Meanwhile, in the circulation circuit 110, the working
medium pump 115 is activated by receiving the activation
instruction, so that the working medium starts to flow. In the
evaporator 111, the heating medium of the heating medium passage
111b heats the working medium of the working medium passage 111a.
In the evaporator 111, the working medium is not sufficiently
evaporated, but only a part of the working medium is evaporated in
the activation state. For this reason, the liquid working medium
also flows out of the evaporator 111, but since the bypass valve
125a is opened, the working medium does not flow into the first
expander 113, but is introduced into the condenser 114 so as to
bypass the first expander 113. At this time, the screw rotor 113b
of the first expander 113 idly rotates by the rotation of the
rotary shaft 123.
[0131] Subsequently, when a difference in pressure obtained from
the detection value of the entering side pressure sensor Ps and the
detection value of the back pressure sensor Pd reaches a
predetermined threshold value, the opening and closing control unit
152 performs control which closes the bypass valve 125a.
Accordingly, the working medium which is evaporated by the
evaporator 111 is introduced into the first expander 113, and the
first expander 113 is driven by the working medium. Accordingly,
the rotor portion 120a of the power generator 120 is driven by the
driving forces of the first expander and the second expander 140.
Subsequently, a general operation is performed.
[0132] As described above, in the power generating apparatus of the
first embodiment, since the heating medium to be introduced into
the evaporator 111 is expanded by the second expander 140, the
pressure of the heating medium introduced into the evaporator 111
is lower than that of the related art. For this reason, the stress
strain generated in the member constituting the evaporator 111 may
be reduced, and hence the burden of the evaporator 111 may be
reduced. Moreover, since the second expander 140 is connected to
the rotary shaft 123 provided with the rotor portion 120a of the
power generator 120, the energy of the heating medium may be
extracted as the driving energy of the rotor portion 120a in the
second expander 140. Accordingly, since the energy of the heating
medium may be used any waste, the performance of the power
generating apparatus may be improved. That is, the pressure of the
heating medium is used in the second expander 140, and the
temperature of the heating medium of which the pressure is
decreased is used in the evaporator 111. Accordingly, the energy of
the heating medium may be more effectively used compared to the
related art.
[0133] Further, in the third embodiment, the bypass valve 25a is
opened when the second expander 140 is driven at a timing earlier
than that of the driving of the first expander 113 by the working
medium. Accordingly, the screw rotor 113b of the first expander 113
may idly rotate. Accordingly, in a case where only the second
expander 140 is driven among the first expander 113 and the second
expander 140 connected to the power generator 120, the first
expander 113 may not serve as a load, and the energy of the heating
medium may be effectively extracted in the second expander 140.
Fourth Embodiment
[0134] FIG. 6 illustrates a rotary machine driving system according
to a fourth embodiment of the present invention. Furthermore, the
same reference numerals as those of the third embodiment will be
given to the same components, and the description thereof will not
be repeated.
[0135] In the third embodiment, the rotary shaft 123 is configured
as one shaft member. On the contrary, in the fourth embodiment, the
rotary shaft 123 is divided into a first shaft portion 123a and a
second shaft portion 123b, and includes a coupling portion 123c
which couples the first shaft portion 123a and the second shaft
portion 123b to each other so as to transmit a driving force
therethrough.
[0136] The coupling portion 123c is configured by a speed
increasing and decreasing mechanism 161 which is provided between
the first shaft portion 123a and the second shaft portion 123b so
as to change the rotation speed. The speed increasing and
decreasing mechanism 161 includes a first gear 161a which is
connected to the first shaft portion 123a and a second gear 161b
which is connected to the second shaft portion 123b and meshes with
the first gear 161a. In the example, the number of teeth of the
first gear 161a is larger than the number of teeth of the second
gear 161b, but instead of this, the opposite configuration may be
employed. Further, in the example, the first shaft portion 123a is
provided with the power generator 120, but instead of this, the
second shaft portion 123b may be provided with the power generator
120.
[0137] One end of the first shaft portion 123a is connected to the
first expander 113. The first gear 161a is coupled to the other end
of the first shaft portion 123a. The second expander 140 is
connected to one end of the second shaft portion 123b. The second
gear 161b is coupled to the other end of the second shaft portion
123b.
[0138] In the fourth embodiment, it is possible to easily handle a
case where the rotation speed of the first expander 113 is
different from the rotation speed of the second expander 140. That
is, in a case where the first expander 113 and the second expander
140 are respectively configured as different types of expanders and
the stated rotation speeds thereof are different from each other,
it is possible to easily handle a difference between both rotation
speeds by providing the speed increasing and decreasing mechanism
161 between the first shaft portion 123a and the second shaft
portion 123b.
[0139] Furthermore, the other configurations and the other
operations and effects are not described, but are the same as those
of the third embodiment.
Fifth Embodiment
[0140] FIG. 7 illustrates a power generating apparatus according to
a fifth embodiment of the present invention. Furthermore, the same
reference numerals as those of the third embodiment will be given
to the same components, and the description thereof will not be
repeated.
[0141] In the fourth embodiment, the coupling portion 123c is
configured as the speed increasing and decreasing mechanism 161. On
the contrary, in the fifth embodiment, the coupling portion 123c is
configured by a magnetic coupling 165 which magnetically couples
the first shaft portion 123a and the second shaft portion 123b to
each other.
[0142] Since the configuration of the magnetic coupling 165 is the
same as the configuration of the first embodiment illustrated in
FIG. 2, the detailed description thereof will not be repeated.
[0143] In the fifth embodiment, since the first shaft portion 123a
accommodated in the casing 113a is axially supported by a bearing
inside the casing 113a, it is possible to prevent a state where a
fluid such as lubricating oil and a working medium leaks to the
outside through the bearing and to connect the first shaft portion
123a and the second shaft portion 123b in a driven state by the
magnetic coupling 165.
[0144] Furthermore, in the fifth embodiment, the second shaft
portion 123b and the inner insertion body 165b are not accommodated
in a hermetic body, but the second shaft portion 123b and the inner
insertion body 165b may be also accommodated in a hermetic
body.
[0145] Further, in the fifth embodiment, the outer cylinder body
165a of the magnetic coupling 165 serves as a driving side and the
inner insertion body 165b serves as a driven side. However, the
inner insertion body 165b may serve as a driving side and the outer
cylinder body 165a may serve as a driven side.
[0146] The other configurations and the other operations and
effects are not described, but are the same as those of the fourth
embodiment.
Sixth Embodiment
[0147] FIG. 8 illustrates a power generating apparatus according to
a sixth embodiment of the present invention. Furthermore, the same
reference numerals as those of the third embodiment will be given
to the same components, and the description thereof will not be
repeated.
[0148] In the sixth embodiment, the water which is used in the
condenser 114 is supplied as lubricant to a bearing 170 of the
rotary shaft 123. That is, in the cooling medium circuit 117, the
downstream passage of the condenser 114 is connected to the bearing
170 of the rotary shaft 123. Accordingly, the cooling medium which
is used to cool the working medium in the cooling medium passage
114b of the condenser 114 may be used as lubricant of the bearing
170. In the example, the cooling medium is introduced into the
bearing 170 disposed inside the second expander 140, but the
bearing 170 may not be disposed inside the second expander 140.
[0149] In the sixth embodiment, lubricating oil does not need to be
used, and it does not take time and effort when discarding
lubricant (water).
[0150] Furthermore, the other configurations and the other
operations and effects are not described, but are the same as those
of the third embodiment.
Seventh Embodiment
[0151] FIG. 9 illustrates a power generating apparatus according to
a seventh embodiment of the present invention. Furthermore, the
same reference numerals as those of the third embodiment will be
given to the same components, and the description thereof will not
be repeated.
[0152] In the seventh embodiment, a rotor portion of a motor 200 is
connected to the rotary shaft 123. That is, the rotor portion of
the motor 200 is connected to the shaft member as a part of the
rotary shaft 123, that is, the shaft member connected to the end
(the right side of FIG. 9) opposite to the first expander 113 in
the screw rotor 140a of the second expander 140. The motor 200 is
exemplified as the rotary machine. The shaft 201 of the motor 200
is connected to a compressor 190, and the compressor 190 is driven
by the rotation of the motor 200. The other configurations are the
same as those of the third embodiment. When driving the compressor
190, the power of the first and second expanders 113 and 140 is
transmitted to the compressor 190 through the rotary shaft 123 and
the shaft 201 connected to the rotary shaft 123. As a result, it is
possible to reduce power consumption compared to a case where the
compressor 190 is driven only by the motor 200.
Other Embodiments
[0153] Furthermore, the present invention of the third to seventh
embodiments is not limited to the above-described embodiments, and
various modifications and improvements may be made without
departing from the spirit of the present invention. For example,
the evaporator 111 may include an evaporation portion which
evaporates the working medium by heating the working medium to a
saturation temperature or so and an overheat portion which keeps
the working medium heated to the saturation temperature or so in
the evaporation portion in an overheat state. In this case, the
evaporation and the overheat portion may be separately provided or
may be integrally provided. In the sixth embodiment, the water
which is condensed from the steam in the evaporator 111 may be used
as lubricant of the bearing 170 of the rotary shaft 123. In the
seventh embodiment, the compressor 190 may be provided on the
rotary shaft 123 so that the compressor 190 is directly driven by
the rotary machine driving system.
* * * * *