U.S. patent application number 11/874320 was filed with the patent office on 2008-05-01 for stirling system and freezer system using the same.
Invention is credited to Fusao Terada.
Application Number | 20080098751 11/874320 |
Document ID | / |
Family ID | 39328511 |
Filed Date | 2008-05-01 |
United States Patent
Application |
20080098751 |
Kind Code |
A1 |
Terada; Fusao |
May 1, 2008 |
STIRLING SYSTEM AND FREEZER SYSTEM USING THE SAME
Abstract
There is disclosed a stirling system in which a rotary-type
high-temperature expansion mechanical section, a rotary-type
low-temperature compression mechanical section and a driving shaft
common to both the mechanical sections are stored in a sealed
container to achieve remarkable simplification and improvement of
durability. In the stirling system, the rotary-type
high-temperature expansion mechanical section and the rotary-type
low-temperature compression mechanical section for constituting a
stirling cycle, and the driving shaft common to both the mechanical
sections are stored in the sealed container. The sealed container
is divided into a rotary-type high-temperature expansion mechanical
section side and a rotary-type low-temperature compression
mechanical section side by a partition wall.
Inventors: |
Terada; Fusao; (Gunma,
JP) |
Correspondence
Address: |
DARBY & DARBY P.C.
P.O. BOX 770, Church Street Station
New York
NY
10008-0770
US
|
Family ID: |
39328511 |
Appl. No.: |
11/874320 |
Filed: |
October 18, 2007 |
Current U.S.
Class: |
62/6 ;
60/519 |
Current CPC
Class: |
F25B 9/14 20130101; F25B
1/04 20130101; F25B 2500/18 20130101 |
Class at
Publication: |
62/6 ;
60/519 |
International
Class: |
F25B 9/14 20060101
F25B009/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2006 |
JP |
2006-319285 |
Claims
1: A stirling system wherein a rotary-type high-temperature
expansion mechanical section and a rotary-type low-temperature
compression mechanical section which constitute a stirling cycle,
and a driving shaft common to both the mechanical sections are
stored in a sealed container, and the sealed container is divided
into a rotary-type high-temperature expansion mechanical section
side and a rotary-type low-temperature compression mechanical
section side by a partition wall.
2: The stirling system according to claim 1, wherein a control
mechanism which controls a performance characteristic of the
stirling cycle, and a generator or a motor are directly connected
to the driving shaft on the rotary-type low-temperature compression
mechanical section side in the sealed container.
3: The stirling system according to claim 1 or 2, wherein a heater,
a cooler and a regenerative heat exchanger which constitute the
stirling cycle are integrated with the sealed container inside or
outside the sealed container.
4: The stirling system according to claim 1 or 2, which further
comprises: a press feed mechanism of a lubricant which lubricates
sliding sections in the sealed container; and a return mechanism
which separates the lubricant from an operation gas discharged from
the sealed container to return the lubricant into the sealed
container.
5: A freezer system in which the stirling system according to claim
1 or 2 is used, the freezer system comprising a motor which drives
a driving shaft and configured to operate a stirling cycle of the
stirling system in a reverse cycle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a stirling system in which
a rotary-type rotary-type high-temperature expansion mechanical
section and a rotary-type low-temperature compression mechanical
section for constituting a stirling cycle are stored in a sealed
container, and a freezer system using the stirling system.
[0003] 2. Description of the Background Art
[0004] Heretofore, a stirling engine (a stirling cycle) as an
external combustion engine is provided with a displacer piston
which reciprocates in a cylinder as one example. Moreover, a
high-pressure operation gas with which the cylinder is filled is
reciprocated between a heating section to be heated by a heating
source such as a combustion gas and a cooling section to be cooled
by a cold source using cooling water. In consequence, a pressure
difference of the operation gas is created in the cylinder, and
this pressure difference is taken out as motive energy via a power
piston which cooperates with the displacer piston with a phase of
90 degrees. Such a constitution has been proposed (see Japanese
Patent Application Laid-Open No. 2006-275018).
[0005] Such a stirling system having a piston system (reciprocating
type) mechanism is a mainstream, and simplification of a stirling
system including a rotary mechanism (a rotary system) has been
investigated. As one example of this simplification, application of
a Wankel type mechanism has scientifically been investigated.
[0006] However, unlike a presently mainstream internal combustion
engine, the stirling system has excellent characteristics such as
high efficiency, variety of fuel and heat source, quietness and
cleanness of exhaust. However, since the former stirling system
receives heat from the outside, internally performs heat exchange
and uses the high-pressure operation gas, the whole mechanism tends
to be complicated and increase a weight thereof. There is much room
for improvement even in durability and response, and the system is
expensive and lacks in market competitiveness. Therefore, the
simplification and cost reduction of the stirling system have been
demanded.
[0007] Moreover, a driving section of the latter Wankel type
mechanism is simplified from a crank mechanism to a rotary
mechanism, but characteristics such as an operation capacity of an
essential fluid operation mechanism are not adapted, a structure is
not integrated, the system is complicated even as a thermal system,
and hence the system has not been put to practical use.
[0008] The present invention has been developed to solve such
problems of the conventional technologies, and an object thereof is
to provide a stirling system in which a rotary-type
high-temperature expansion mechanical section, a rotary-type
low-temperature compression mechanical section and a driving shaft
common to both the mechanical sections are stored in a sealed
container to achieve remarkable simplification and improvement of
durability, and a freezer system using the stirling system.
SUMMARY OF THE INVENTION
[0009] A stirling system of a first invention is characterized in
that a rotary-type high-temperature expansion mechanical section
and a rotary-type low-temperature compression mechanical section
which constitute a stirling cycle, and a driving shaft common to
both the mechanical sections are stored in a sealed container and
that the sealed container is divided into a rotary-type
high-temperature expansion mechanical section side and a
rotary-type low-temperature compression mechanical section side by
a partition wall.
[0010] Moreover, a stirling system of a second invention is
characterized in that in the above invention, a control mechanism
which controls a performance characteristic of the stirling cycle,
and a generator or a motor are directly connected to the driving
shaft on the rotary-type low-temperature compression mechanical
section side in the sealed container.
[0011] Furthermore, a stirling system of a third invention is
characterized in that in the first or second invention, a heater, a
cooler and a regenerative heat exchanger which constitute the
stirling cycle are integrated with the sealed container inside or
outside the sealed container.
[0012] In addition, a stirling system of a fourth invention is
characterized in that any one of the first to third inventions
further comprises: a press feed mechanism of a lubricant which
lubricates sliding sections in the sealed container; and a return
mechanism which separates the lubricant from an operation gas
discharged from the sealed container to return the lubricant into
the sealed container.
[0013] Moreover, a freezer system of a fifth invention is
characterized by comprising a motor which drives a driving shaft
and operating a stirling cycle of the stirling system according to
any one of the first to fourth inventions in a reverse cycle.
[0014] According to the first invention, the rotary-type
high-temperature expansion mechanical section and the rotary-type
low-temperature compression mechanical section which constitute the
stirling cycle, and the driving shaft common to both the mechanical
sections are stored in the sealed container, and the sealed
container is divided into the rotary-type high-temperature
expansion mechanical section side and the rotary-type
low-temperature compression mechanical section side by the
partition wall. Therefore, in a case where the control mechanism
which controls the performance characteristic of the stirling
cycle, and the generator or the motor are directly connected to the
driving shaft on the rotary-type low-temperature compression
mechanical section side in the sealed container, response of power
transmission can remarkably be improved. Since the rotary-type
high-temperature expansion mechanical section and the rotary-type
low-temperature compression mechanical section are stored in the
sealed container, the control mechanism and the generator or the
motor are not directly impacted from the outside, and can avoid
wind and rain. In consequence, it can securely be prevented that
the control mechanism and the generator and the motor are corroded
by damages, wind and rain, and hence durability of the stirling
system can largely be improved.
[0015] Especially, since the rotary-type high-temperature expansion
mechanical section and the rotary-type low-temperature compression
mechanical section are stored in the sealed container, remarkable
simplification and durability of the stirling system can be
secured. In consequence, since the compact stirling system can be
realized, a weight of the system can largely be reduced as compared
with, for example, the conventional stirling system. Therefore,
productivity can remarkably be improved, costs can largely be
reduced, and market competitiveness of the stirling system can
generally largely be improved.
[0016] Moreover, according to the third invention, in addition to
the first or second invention, the heater, the cooler and the
regenerative heat exchanger which constitute the stirling cycle are
integrated with the sealed container inside or outside the sealed
container, so that the stirling system can easily be conveyed
anywhere and installed anywhere. In consequence, a conveying
property, an installing property and the like of the stirling
system can largely be improved, and versatility of the stirling
system can remarkably be improved.
[0017] Furthermore, according to the fourth invention, in addition
to any one of the first to third inventions, since the system
further comprises the press feed mechanism of the lubricant which
lubricates the sliding sections in the sealed container and the
return mechanism which separates the lubricant from the operation
gas discharged from the sealed container to return the lubricant
into the sealed container, the lubricant can smoothly be supplied
to the respective sliding sections of the stirling cycle. Since the
system includes the return mechanism which separates the lubricant
from the operation gas to return the lubricant into the sealed
container, for example, a disadvantage that the lubricant is mixed
with the operation gas and surplus lubricant flows into the
rotary-type low-temperature compression mechanical section and the
like can be avoided. In consequence, an operation of the stirling
cycle can smoothly be performed, and prevention of output
deterioration, performance deterioration of the stirling cycle and
the like can securely be prevented.
[0018] In addition, according to the fifth invention, the freezer
system comprises the motor which drives the driving shaft and
operates the stirling cycle of the stirling system according to any
one of the first to fourth inventions in the reverse cycle, so that
the freezer system can be constructed using compression and
expansion of the operation gas accompanying operations of the
rotary-type low-temperature compression mechanical section and the
rotary-type high-temperature expansion mechanical section. When a
natural operation fluid such as hydrogen or helium is used in the
operation gas, the system can be applied even to a freezer field
having an excellent environmental property. Therefore, both of the
generator and the freezer can be used, and convenience of the
stirling system can largely be improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a vertical side view (a partially schematic
diagram) of a stirling system according to one embodiment of the
present invention; and
[0020] FIG. 2 is a conceptual diagram of the stirling system
according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The present invention is mainly characterized in that a
weight of a stirling system is reduced to raise productivity in
order to improve energy efficiency and market competitiveness. A
purpose of improving the energy efficiency to raise the
productivity is realized by a simple structure in which a
rotary-type high-temperature expansion mechanical section and a
rotary-type low-temperature compression mechanical section are only
stored in a sealed container.
[0022] Next, an embodiment of the present invention will be
described in detail with reference to the drawings. FIG. 1 is a
vertical side view (a schematic diagram) of a stirling system 10
according to one embodiment of the present invention, and FIG. 2 is
a conceptual diagram of the stirling system 10 according to the
embodiment of the present invention. As shown in FIG. 1, the
stirling system 10 of the present invention includes a cylindrical
sealed container 12 formed of a steel plate, and driving mechanical
sections (a rotary-type high-temperature expansion mechanical
section 24 and a rotary-type low-temperature compression mechanical
section 44) are arranged and stored in this sealed container
12.
[0023] The rotary-type high-temperature expansion mechanical
section 24 is arranged on one side (on the upside in the drawing)
of the sealed container 12, and the rotary-type low-temperature
compression mechanical section 44 is disposed on the other side
(the downside in the drawing) of the sealed container 12. Both the
mechanical sections 24, 44 are fixed to a common driving shaft 14
disposed over a longitudinal direction of the sealed container 12,
and a press feed mechanism 15 is disposed on the other side (the
downside in the drawing) of this driving shaft 14. The press feed
mechanism 15 presses and feeds a lubricant 70 (corresponding to the
lubricant of the present invention) stored on the other side of the
sealed container 12 from a supply passage of the lubricant 70
disposed beforehand in the sealed container 12 to sliding sections
where a first rotor 28 (including a first vane 30), a second rotor
48 (including a second vane 50), the rotary-type low-temperature
compression mechanical section 44 and the like slide to lubricate
the sections. This press feed mechanism 15 presses and feeds the
lubricant 70 into a first cylinder 26 and a second cylinder 46 with
a centrifugal force generated by rotating, for example, a spirally
curved spiral groove or a propeller-like portion. It is to be noted
that a technology of press-feeding the lubricant 70 with the press
feed mechanism 15 has heretofore been a well-known technology, and
hence detailed description is omitted.
[0024] A partition wall 16 is disposed between the rotary-type
high-temperature expansion mechanical section 24 and the
rotary-type low-temperature compression mechanical section 44, and
the sealed container 12 is divided into a rotary-type
high-temperature expansion mechanical section 24 side and a
rotary-type low-temperature compression mechanical section 44 side
by this partition wall 16. That is, the rotary-type
high-temperature expansion mechanical section 24 is disposed on one
side (the upside in the drawing) of the partition wall 16, and the
rotary-type low-temperature compression mechanical section 44 is
disposed on the other side (the downside in the drawing). The
partition wall 16 includes an insulation wall using a porous
material and having a high insulation property or an insulation
wall provided with an inner vacuum space and having a high
insulation property, and preferably insulates between the
rotary-type high-temperature expansion mechanical section 24 and
the rotary-type low-temperature compression mechanical section 44.
A control mechanism 18 is disposed between the rotary-type
low-temperature compression mechanical section 44 and the partition
wall 16 with a predetermined space from the partition wall 16, and
a generator 20 is disposed between the rotary-type low-temperature
compression mechanical section 44 and the press feed mechanism 15
so as to substantially come in close contact with an inner surface
of the sealed container 12 and have a predetermined space from the
control mechanism 18. A predetermined space is disposed around the
control mechanism 18, and this space is provided with a second
space 44A. This control mechanism 18 preferably controls a
performance characteristic of the stirling system 10, and
preferably regulates phase angles of compression upper dead points
of both of the rotary-type high-temperature expansion mechanical
section 24 and the rotary-type low-temperature compression
mechanical section 44.
[0025] Moreover, the generator 20 is a generator which is also
usable as a motor and in which power generation and the motor are
so-called reversibly usable. This generator 20 generates power to
output the power during an operation of the stirling system 10
(during rotation of the driving shaft 14). The generator 20 is
constituted so that a power source externally disposed beforehand
is energized to operate the generator 20 as the motor at the start
of the stirling system 10 and that the motor automatically switches
to the generator 20 at a time when a sufficient shaft output is
generated. In such a sealed container 12, the rotary-type
high-temperature expansion mechanical section 24, the rotary-type
low-temperature compression mechanical section 44, the control
mechanism 18, the generator 20 and the lubricant 70 are contained.
In consequence, a simple and optimum shape structure of the
stirling system 10 is realized, and performance, capacity and
weight of the system are constituted so as to obtain pressure air
tightness, cost reduction, practicality and convenience. It is to
be noted that the control mechanism 18 will be described later in
detail.
[0026] Here, a mechanical section of a rolling piston type will
hereinafter be described as an example. The rotary-type
high-temperature expansion mechanical section 24 includes the first
cylinder 26 having an outer peripheral surface substantially
brought into close contact with the inner surface of the sealed
container 12 and the first rotor 28 rotatably disposed in this
first cylinder 26. The rotary-type high-temperature expansion
mechanical section 24 has predetermined capacity spaces at both of
a space between the partition wall 16 and the first cylinder 26 and
a space between the first cylinder 26 and a surface on the side
(the upside in FIG. 1) opposite to the partition wall 16 to form a
first space 24A. The first cylinder 26 includes the first vane 30
whose tip end portion usually abuts on the first rotor 28, and the
first cylinder 26 is divided into a high-temperature discharge side
and a high-temperature suction side by this first vane 30. That is,
the first cylinder 26 is divided into a high-temperature side
discharge port 34 of the first vane 30 as the high-temperature
discharge side and a high-temperature side suction port 32 side as
the high-temperature suction side by the first vane 30 (shown in
FIG. 2).
[0027] The center of the first rotor 28 is fixed to a crank shaft
14A (a solid line in FIG. 2) of the driving shaft 14 (a dotted line
in FIG. 2), and this driving shaft 14 crank-rotates, whereby the
first rotor rolls in the first cylinder 26. That is, the first
rotor 28 rolls around a rotary shaft center which is the center of
the first cylinder 26 in the first cylinder 26. The first cylinder
26 is provided with a heater 38A (shown in FIG. 2) which supports
the isothermal heating of the operation gas to be sucked on the
high-temperature suction side.
[0028] Moreover, the rotary-type low-temperature compression
mechanical section 44 includes the second cylinder 46 having an
outer peripheral surface substantially brought into close contact
with the inner surface of the sealed container 12 and the second
rotor 48 rotatably disposed in the second cylinder 46. The second
cylinder 46 is provided with the second vane 50 whose tip end
portion usually abuts on the second rotor 48, and the second
cylinder 46 is divided by this second vane 50. That is, the second
cylinder 46 is divided into a low-temperature side discharge port
54 side of the second vane 50 as a low-temperature discharge side
and a low-temperature side suction port 52 side as a
low-temperature suction side by the second vane 50 (shown in FIG.
2). The stirling system 10 includes a rotary mechanism (a rolling
piston type) having the first rotor 28 and the second rotor 48
disposed in the rotary-type high-temperature expansion mechanical
section 24 and the rotary-type low-temperature compression
mechanical section 44, respectively.
[0029] The second rotor 48 is fixed to the crank shaft 14A of the
driving shaft 14, and this driving shaft 14 crank-rotates, whereby
the second rotor rolls in the second cylinder 46. That is, the
second rotor 48 rolls around a rotary shaft center which is the
center of the second cylinder 46 in the second cylinder 46. The
second cylinder 46 is provided with a cooler 58A (shown in FIG. 2)
which supports the isothermal cooling of the operation gas sucked
into the low-temperature suction side from the outside of the
second cylinder 46.
[0030] The high-temperature side discharge port 34 of the first
cylinder 26 constituting the rotary-type high-temperature expansion
mechanical section 24 is connected to a hollow connection pipe 36,
and this connection pipe 36 is connected to the low-temperature
side suction port 52 of the second cylinder 46 constituting the
rotary-type low-temperature compression mechanical section 44 via a
first cooler 58 (a dotted line in FIG. 1). The low-temperature side
discharge port 54 of the second cylinder 46 is connected to a
hollow connection pipe 56. This connection pipe 56 is connected to
the high-temperature side suction port 32 of the first cylinder 26
constituting the rotary-type high-temperature expansion mechanical
section 24 via a first heater 38 (a solid line in FIG. 1).
[0031] A regenerative heat exchanger 60 requires a function of
accumulating heat to preliminarily cool the operation gas at a time
when the gas flows into the regenerative heat exchanger 60 from the
rotary-type high-temperature expansion mechanical section 24 side
at a high temperature, and discharging heat to preliminarily heat
the operation gas at a time when the gas flows into the exchanger
from the rotary-type low-temperature compression mechanical section
44 side. The regenerative heat exchanger 60 includes, for example,
a double piping line, a plate type sensible heat exchanger
structure and the like so that flows (counter flows) of the
operation gas passing in opposite directions in the exchanger are
not mixed, and heat exchange is facilitated. In this case, the
regenerative heat exchanger 60 performs only sensible heat exchange
of the operation gas, and hardly accumulates or discharges the
heat. Such a regenerative heat exchanger 60 does not require any
complicated internal filler such as mesh, and constituted in a
comparatively small capacity.
[0032] The regenerative heat exchanger 60 and a return mechanism 62
are important elements constituting the present invention, and are
arranged outside the sealed container 12 in principle. That is, in
the stirling system 10, the first cylinder 26, the regenerative
heat exchanger 60, the return mechanism 62, the first cooler 58,
the second cylinder 46, the return mechanism 62, the regenerative
heat exchanger 60, the first heater 38 and the first cylinder 26
are successively connected to one another via pipes to constitute
an annular operation gas circulation circuit (hereinafter referred
to as the stirling cycle). It is to be noted that in FIG. 2, the
regenerative heat exchanger 60, the return mechanism 62, the first
heater 38, the second heater 38A, the first cooler 58 and the
second cooler 58A arranged outside the sealed container 12 are
shown by dotted lines.
[0033] Moreover, a predetermined amount of a high-pressure
operation gas such as a hydrogen gas, a helium gas or a nitrogen
gas is introduced as the operation gas in the stirling cycle, and a
predetermined amount of silicon-based oil is introduced as the
lubricant 70 for use in the stirling cycle. Conditions such as a
pressure and an inner capacity of the operation gas introduced in
the stirling cycle, eccentricities of the first rotor 28 and the
second rotor 48, a difference between the phase angles of the
rotors, inflow and discharge heat amounts and a temperature are
selected and set beforehand so as to constitute the stirling
cycle.
[0034] Furthermore, the return mechanism 62 separates the lubricant
70 from the operation gas and removes deposit to return the
lubricant into a lower part of the sealed container 12, and
includes, for example, a gear pump and a filter having a lubricant
70 separating function of adsorbing the lubricant 70 to separate
the lubricant from the operation gas. That is, the return mechanism
62 returns the lubricant 70 separated from the operation gas by the
return mechanism 62 into the lower part of the sealed container 12
(the downside in FIG. 1) with a gear pump via a connection pipe 63
(a one dot chain line in FIG. 1).
[0035] Here, the conventional stirling cycle of the reciprocation
system is usually formed by laminating a finely meshed metal in
multiple layers, because the operation gas including the lubricant
reciprocates between the rotary-type high-temperature expansion
mechanical section (a high-temperature section) at a high
temperature and the rotary-type low-temperature compression
mechanical section (a low-temperature section) at a low
temperature. In consequence, the regenerative heat exchanger is
constituted so that the operation gas touches a large contact area,
and sufficient heat accumulation and discharge effects are obtained
with a fluid resistance which is as small as possible. However,
when the lubricant is heated at the high-temperature section to
change a property thereof and the deposit is generated, the
regenerative heat exchanger through which the lubricant passes
before reaching the low-temperature section might be clogged.
Therefore, lubrication in the stirling cycle by use of the
lubricant and sealing cannot sufficiently be performed.
[0036] To solve the problem, in the present invention, the press
feed mechanism 15 which press-feeds the lubricant 70 stored in the
lower part of the sealed container 12 to the respective sliding
sections is disposed. Moreover, the filter which separates the
lubricant 70 from the operation gas and which removes the deposit
is disposed in the return mechanism 62. In consequence, it is
constituted that the deposit generated in the lubricant 70 is
removed and that the lubrication and the sealing of the stirling
cycle are preferably performed. Furthermore, the stored lubricant
70 is fed under pressure to the respective sliding portions again
by the press feed mechanism 15 to cool the sliding sections and
prevent wear on the sections. It is to be noted that the return
mechanism 62 may be modified so that, in a case where the use of
the lubricant 70 at the rotary-type high-temperature expansion
mechanical section 24 is to be inhibited owing to a disadvantage
that the section is thermally and easily damaged, the lubricant is
separated from the operation gas circulated in the stirling cycle
and used in the only rotary-type low-temperature compression
mechanical section 44. It is to be noted that a technology of
feeding the lubricant 70 under pressure with the gear pump is a
heretofore well-known technology, and hence detailed description
thereof is omitted.
[0037] Next, an operation of the stirling system 10 will be
described. It is to be noted that the operation gas is heated by
the first heater 38 to reach the high temperature at the
rotary-type high-temperature expansion mechanical section 24, and
the gas is cooled by the second cooler 58A to reach the low
temperature at the rotary-type low-temperature compression
mechanical section 44. Therefore, since it is thermodynamically
advantageous to vertically dispose the sealed container 12 for use
so that the rotary-type high-temperature expansion mechanical
section 24 is positioned at an upper part and the rotary-type
low-temperature compression mechanical section 44 is positioned at
a lower part, a state in which the sealed container 12 is
vertically disposed will be described in the embodiment. The
control mechanism 18 and the generator 20 are arranged in the same
space as the rotary-type low-temperature compression mechanical
section 44 side in order to prevent the heating. As a heating
source of the first heater 38 (including the second heater 38A),
for example, fossil fuel, biomass fuel, micro gas turbine or fuel
cell exhaust heat, factory exhaust heat, solar heat or the like is
used. As a cooling source of the first cooler 58 (including the
second cooler 58A), for example, underground water, river water,
pond water, seawater, air (outside air at ordinary temperature) or
the like is used. Namely, the first heater 38 and the second heater
38A are heated by the heating source. The isothermal heating of the
first cylinder 26 is made by the second heater 38A. The first
cooler 58 and the second cooler 58A are cooled by the cooling
source. And the isothermal cooling of the second cylinder 46 is
made by the second cooler 58A.
[0038] Moreover, both the rotors 28, 48 which come in contact with
the inner surfaces of the cylinders 26, 46 to roll are set based on
basic points of both the vanes 30, 50 so that the difference
between the phase angles is about 180 degrees. In this case, the
first cylinder 26 and the second cylinder 46 are arranged so that
eccentric directions are set to opposite phases so as to cancel
vibrations and obtain a low vibration. It is to be noted that a
phase angle difference of 180 degrees indicates a time when the
discharge of the operation gas from the rotary-type
high-temperature expansion mechanical section 24 is started, and
suction of the operation gas into the rotary-type low-temperature
compression mechanical section 44 is started. The first rotor 28 is
connected to the second rotor 48 by the driving shaft 14, and the
high-temperature side suction port 32, the low-temperature side
suction port 52, the high-temperature side discharge port 34 and
the low-temperature side discharge port 54 of both of the cylinders
26, 46 are disposed on the same side surface.
[0039] Furthermore, the operation gas which flows into the first
cylinder 26 (the high-temperature suction side) is heated by the
first heater 38. Since the first cylinder 26 is heated by the
second heater 38A, the operation gas substantially isothermally
expands, a predetermined high pressure is obtained in the first
cylinder 26. This high-pressure operation gas allows the first
rotor 28 to roll along the inner surface of the first cylinder 26
in a clockwise direction (an arrow in FIG. 2), and the operation
gas is sucked from the connection pipe 56 into the high-temperature
suction side. Moreover, the lubricant 70 is fed under pressure to
the respective sliding sections, the first cylinder 26 and the
second cylinder 46 by the press feed mechanism 15. In this manner,
the rotary-type high-temperature expansion mechanical section 24
obtains a driving force from the heating source to rotate the
driving shaft 14.
[0040] When the first rotor 28 rolls, the operation gas in the
first cylinder 26 (on the high-temperature discharge side) is
discharged into the connection pipe 36 from the high-temperature
side discharge port 34. The operation gas discharged into the
connection pipe 36 travels in an arrow direction (a rightward arrow
in FIG. 2) to flow into the regenerative heat exchanger 60. The
operation gas which has flowed into the regenerative heat exchanger
60 performs heat exchange between the gas and the operation gas
cooled by the second cylinder 46, and is cooled (preliminarily
cooled). The operation gas which has exited from the regenerative
heat exchanger 60 flows into the return mechanism 62 where the
operation gas is separated from the lubricant 70. The operation gas
separated from the lubricant 70 flows into the first cooler 58, and
is cooled, and then flows from the low-temperature side suction
port 52 into the second cylinder 46 (the low-temperature suction
side). It is to be noted that the lubricant 70 fed under pressure
by the press feed mechanism 15 circulates with the operation gas in
the rotary-type high-temperature expansion mechanical section 24,
and performs sufficient lubrication and sealing of the stirling
cycle together with the operation gas.
[0041] At this time, the operation gas in the second cylinder 46
(the low-temperature discharge side) is cooled by the second cooler
58A. When this operation gas is cooled, the gas is substantially
isothermally compressed, whereby a volume of the operation gas is
compressed in the second cylinder 46. The second rotor 48 rolls
along the inner surface of the second cylinder 46 in the clockwise
direction (an arrow in FIG. 2), and the operation gas is sucked
from the connection pipe 36 on the low-temperature suction side.
Then, the operation gas in the second cylinder 46 (on the
low-temperature discharge side) is discharged from the
low-temperature side discharge port 54 into the connection pipe 56.
The operation gas discharged into the connection pipe 56 travels in
an arrow direction (a leftward arrow in FIG. 2), and the operation
gas is separated from the lubricant 70 in the return mechanism 62.
The operation gas separated from the lubricant 70 flows into the
regenerative heat exchanger 60, performs heat exchange between the
gas and the operation gas heated by the first cylinder 26, and is
heated (preliminarily heated).
[0042] Then, after the heated operation gas is heated by the first
heater 38, the gas returns from the high-temperature side suction
port 32 into the first cylinder 26 (on the high-temperature suction
side). In this manner, the rotary-type high-temperature expansion
mechanical section 24 obtains a driving force to rotate the driving
shaft 14. In the whole stirling system 10, since functions are
simply shared by components such as the regenerative heat exchanger
60, the first heater 38 and the first cooler 58 based on the
operation gas in the stirling system 10, the system is
fundamentally simplified, and a continuous operation can be
performed. A flow of the operation gas in the regenerative heat
exchanger 60 is not a reciprocating flow, and is divided into the
connection pipe 36 and the connection pipe 56 between the
high-temperature section (the rotary-type high-temperature
expansion mechanical section 24) and the low-temperature section
(the rotary-type low-temperature compression mechanical section
44), and counter flows of one-directional flows are constituted so
that the heat exchange between the flows can be performed.
[0043] That is, in the stirling system 10, the rotary-type
high-temperature expansion mechanical section 24 operates to
produce the driving force and drives the driving shaft 14, and
power is generated by the generator 20 fixed to the driving shaft
14. The stirling system 10 performs a compressing or expanding
function to generally produce an output in a state in which both of
the rotary-type high-temperature expansion mechanical section 24
and the rotary-type low-temperature compression mechanical section
44 are nearly isothermal. After an external heat source is added to
the first heater 38 and the second heater 38A, conducted to the
operation gas and converted into the power, the heat is discharged
as the exhaust heat from the first cooler 58 and the second cooler
58A. As a result, thermodynamic stages are continuously realized to
complete the stirling cycle, and the system functions as an
engine.
[0044] Here, in the stirling cycle as an external combustion
engine, since the heat is obtained from the outside, responsive
reaction to the power transmission is delayed in relation to the
heat conduction. An ideal phase angle difference with which this
stirling cycle can exhibit a maximum capability is 180 degrees.
When the difference of the phase angle is 0 degree, the system does
not operate. However, when the phase angle is 180 degrees, a
thermodynamical capability is not necessarily 100%. To solve the
problem, it is constituted that the phase angle can be regulated by
the control mechanism 18 so as to obtain the maximum outputs from
the rotary-type high-temperature expansion mechanical section 24
and the rotary-type low-temperature compression mechanical section
44. It is also constituted that the phase angle can be regulated
during the operation of the stirling cycle so as to vary the
driving force.
[0045] That is, the control mechanism 18 has a function of
appropriately changing a rotary phase difference between the first
rotor 28 of the rotary-type high-temperature expansion mechanical
section 24 and the second rotor 48 of the rotary-type
low-temperature compression mechanical section 44 so that a
thermodynamic characteristic of the stirling cycle is changed to
control the performance characteristic. Examples of a structure of
the control mechanism 18 include a structure in which a gear
disposed at the driving shaft 14 on the rotary-type
high-temperature expansion mechanical section 24 side engages with
a gear disposed on the opposite rotary-type low-temperature
compression mechanical section 44 side to regulate the phase angle
and a structure in which the phase angle is regulated with an
electromagnetic clutch or the like. The phase angle difference
between the rotors 28 and 48 is set to about 180 degrees based on
both the vanes 30, 50 as the basic points as described above, but
the control mechanism 18 freely changes this phase angle difference
to exhibit the maximum capability of the stirling cycle.
[0046] Moreover, in the stirling cycle, in a case where a load
decreases in a short time (e.g., within about one minute) to reduce
the capability, even when an input (heating and cooling) is reduced
to the half, the capability cannot easily be reduced owing to an
influence of remaining heat and inertia. To solve the problem, when
the control mechanism 18 displaces the phase angle difference as
much as a predetermined angle, the capability can be reduced.
Therefore, when the load is varied, the output (the power) of the
generator 20 can be changed, so that it is possible to prevent a
disadvantage that an amount of the power to be generated
excessively increases at a time when the load is reduced. It is to
be noted that a technology of the control mechanism 18 to displace
the phase angles of both the rotors 28, 48 by engagement of the
gears, by use of the electromagnetic clutch or the like is a
heretofore well-known technology, and hence detailed description
thereof is omitted.
[0047] Furthermore, since the operation gas flows in only one
direction in the present stirling cycle, the clogging of the
regenerative heat exchanger 60 is not easily caused, so that the
stirling cycle using the lubricant 70 can safely be constructed.
When the lubricant 70 is circulated through the stirling cycle,
sealability and lubricating property can remarkably be improved as
compared with the conventional technology. In consequence, the
first heater 38, the first cooler 58 and the regenerative heat
exchanger 60 forming the basis of the present invention can be
integrated with the sealed container 12 inside or outside the
sealed container 12, and the system can largely be simplified.
Therefore, the performance characteristic of the stirling system 10
can largely be improved. Moreover, preparation precisions,
materials, surface treatments and the like of the rotary-type
high-temperature expansion mechanical section 24 and the
rotary-type low-temperature compression mechanical section 44 can
remarkably be simplified.
[0048] In addition, since the control mechanism 18, the generator
20 and the like are stored in the rotary-type low-temperature
compression mechanical section 44 side of the sealed container 12,
a mechanism to extract an output shaft (the driving shaft 14) from
the sealed container 12 becomes unnecessary, and leakage of the
operation gas can be prevented. Furthermore, the system might not
be damaged owing to be heated excessively. Since the generator 20
is disposed in the second space 44A, a generated heat content can
be cooled to avoid the superheat in a case where the generator 20
is used as the motor, As a result, when the control mechanism 18,
the generator 20 and the like are brought into close contact with
the sealed container 12, the sealed container 12 can be
miniaturized, and conveying property and installing property can
remarkably be improved.
[0049] Moreover, in the stirling cycle, when the rotary-type
high-temperature expansion mechanical section 24 side and the
rotary-type low-temperature compression mechanical section 44 side
usually perform heating and cooling or substantially isothermal
expansion and substantially isothermal compression, and
thermodynamic cycles of substantial iso-capacity movements are
arranged so as to aid with each other between the first cylinder 26
and the second cylinder 46 (effect of heat reuse and regeneration),
so that innovative, rational and high efficient heat cycle which
has not heretofore been obtained can be realized. It is to be noted
that practically in the stirling cycle, even when a step portion of
the substantial iso-capacity movement deviates and changes in a
isobaric movement (referred to as an Erickson cycle) direction, the
system having the basic constitution according to the present
invention can obtain the above-mentioned excellent characteristics
as it is. Therefore, it can be recognized that an effect of heat
reuse and regeneration is equivalent to that of the stirling
cycle.
[0050] As described above, in the stirling cycle of the present
invention, the rotary-type high-temperature expansion mechanical
section 24, the rotary-type low-temperature compression mechanical
section 44 and the driving shaft 14 common to both the mechanical
sections are stored in the sealed container 12. The sealed
container 12 is divided into the rotary-type high-temperature
expansion mechanical section 24 side and the rotary-type
low-temperature compression mechanical section 44 side by the
partition wall 16. Therefore, when the control mechanism 18 to
control the performance characteristic of the stirling cycle and
the generator 20 (the generator can be the motor) are directly
connected to the driving shaft 14 on the rotary-type
low-temperature compression mechanical section 44 side in the
sealed container 12, the response to the power transmission can
remarkably be improved. Since the rotary-type high-temperature
expansion mechanical section 24 and the rotary-type low-temperature
compression mechanical section 44 are stored in the sealed
container 12, the control mechanism 18, the generator 20 (the
motor) and the like are not directly impacted from the outside, and
wind and rain can be avoided. In consequence, it can securely be
prevented that the control mechanism 18 and the generator 20 (the
motor) are corroded by damages, wind and rain, and hence durability
of the stirling system can largely be improved. Therefore, in the
stirling cycle of the present system, the control mechanism 18
changes the phase difference between both the rotors 28 and 48 of
the rotary-type high-temperature expansion mechanical section 24
and the rotary-type low-temperature compression mechanical section
44, so that generation of a stirling cycle state in which capacity
changes of both the simplest mechanical sections are mutually
optimum with excellent response. However, when this control is not
required, the control mechanism 18 is unnecessary.
[0051] In consequence, the system having stirling engine
characteristics such as high efficiency, variety of fuel and heat
source, quietness and cleanness of exhaust can be put into
practical use with a simple structure in which the driving
mechanical sections (the rotary-type high-temperature expansion
mechanical section 24 and the rotary-type low-temperature
compression mechanical section 44) are sealed and integrated. Since
the sealed container 12 is constituted to be cylindrical, pressure
resistance, reliability and compactness can rapidly be improved,
and the system can be utilized in a general energy apparatus
application field requiring convenience, energy saving property,
environment consciousness and the like which have not been obtained
with an existing engine such as a conventional internal combustion
engine.
[0052] Especially, Since the rotary-type high-temperature expansion
mechanical section 24 and the rotary-type low-temperature
compression mechanical section 44 are stored in the sealed
container 12, when the sealed container 12 and both mechanical
section 24 and 44 are constructed to arrange the center of driving
shaft 14 in a straight line, the centering of the driving shaft 14
can be made very easily. In consequence, the stirling system 10 can
be assembled easily, and hence remarkable cost reduction of the
stirling system 10 can be achieved. And since the driving
mechanical section is stored in the sealed container 12, the
remarkable simplification and durability of the stirling system 10
can be secured. Since the compact stirling cycle is obtained, the
weight of the system can largely be reduced as compared with the
conventional stirling cycle. In consequence, the productivity can
remarkably be improved, and costs can be reduced, so that the
market competitiveness of the stirling system 10 can generally
largely be improved.
[0053] Moreover, since the heater (the first heater 38 and the
second heater 38A), the cooler (the first cooler 58 and the second
cooler 58A) and the regenerative heat exchanger 60 for constituting
the stirling cycle are integrated with the sealed container 12
inside or outside the sealed container 12, the stirling system 10
can easily be conveyed anywhere or can easily be installed
anywhere. In consequence, conveying property, installing property
and the like of the stirling system 10 can largely be improved, and
versatility of the stirling system 10 can remarkably be
improved.
[0054] Furthermore, since the system includes the press feed
mechanism 15 of the lubricant 70 for lubricating the sliding
sections in the sealed container 12 and the return mechanism 62 for
separating the lubricant 70 from the operation gas discharged from
the sealed container 12 to return the lubricant into the sealed
container 12, the lubricant 70 can smoothly be supplied to the
respective sliding sections of the stirling cycle. Since the system
includes the return mechanism 62 for separating the lubricant 70
from the operation gas to return the lubricant into the sealed
container 12, a disadvantage that the lubricant 70 is mixed with
the operation gas to flow into the rotary-type low-temperature
compression mechanical section 44 and the like can be avoided. In
consequence, the stirling cycle can smoothly be operated, output
deterioration can be prevented, and performance deterioration of
the stirling cycle and the like can securely be prevented.
[0055] In addition, when the system includes the motor 20 to drive
the driving shaft 14 and operates the stirling cycle in a reverse
cycle (namely rotating the driving shaft 14 to anticlockwise in
FIG. 2 and reversing the flowing direction of the operation gas),
the freezer system can be constructed using the compression and
expansion of the operation gas accompanying the operations of the
rotary-type low-temperature compression mechanical section 44 and
the rotary-type high-temperature expansion mechanical section 24.
In this case, the first heater 38 and the second heater 38A may
work as suction heat cooling section, whereby the heat can be
absorbed from the outside to cool a target. The first cooler 58 and
the second cooler 58A may work as discharge heat heater to
discharge the heat to the outside. Practically, the system can be
applied to a heat pump air conditioner, a fluid and low temperature
chiller and an extremely low temperature freezer. When a natural
operation fluid such as hydrogen or helium is used in the operation
gas, the system can be applied even to a freezer field having an
excellent environmental property. Therefore, both of the generator
20 and the freezer can be used, and convenience of the stirling
system can largely be improved.
[0056] Moreover, it can be expected that the system can be put into
practical use with a performance which is far superior to that of
the conventional reciprocating type stirling cycle and with reduced
costs. Since the eccentric directions of the first cylinder 26 and
the second cylinder 46 are set so as to obtain reverse phases and
vibrations are cancelled mutually, a noise level can largely be
reduced. It is to be noted that in either the output from the
generator 20 or the freezer system, a practical cycle slightly
deviates from a thermodynamically ideal stirling cycle when
operating, but it is an essential feature of the present invention
to preserve the scope of the present invention based on the heat
regenerating cycle. The structure of the stirling cycle is similar
to an already popular structure usually referred to as "a sealed
type two-cylinder system rotary compressor" in a compressor for
freezer air conditioning, and excellent productivity and cost
reduction can similarly be expected based on simplicity of the
structure.
[0057] It is to be noted that in the embodiment, the sealed
container 12 constituting the stirling cycle is vertically
installed (the rotary-type high-temperature expansion mechanical
section 24 is disposed on the upside and the rotary-type
low-temperature compression mechanical section 44 is disposed on
the downside), but the sealed container 12 may not be installed
vertically but may be installed horizontally (a state in which the
rotary-type high-temperature expansion mechanical section 24 and
the rotary-type low-temperature compression mechanical section 44
are sufficiently horizontally installed). In this case, it is
necessary to change the structure to a structure in which the
lubricant 70 can sufficiently be supplied to the respective driving
mechanical sections in the substantially horizontal state of the
sealed container 12, that is, a structure in which a lower end of
the press feed mechanism 15 opens in the lubricant 70 so as to pump
up the lubricant 70 and feed the lubricant under pressure at a time
when the sealed container 12 is horizontally disposed. In
consequence, a degree of freedom in posture of the sealed container
12 can be secured, and the whole stirling system 10 can be
constituted to be compact.
[0058] In addition, after the operation gas which has flows into
the first cylinder 26 from the high-temperature side suction port
32 of the rotary-type high-temperature expansion mechanical section
24 passes through the first heater 38, and further passes through
the first space 24A to heat the first cylinder 26 from the outside,
the gas may flow into the first cylinder 26 from the
high-temperature side suction port 32.
[0059] Similarly, after the operation gas which has flowed into the
second cylinder 46 from the low-temperature side suction port 52 of
the rotary-type low-temperature compression mechanical section 44
passes through the first cooler 58, and further passes through the
second space 44A to heat the second cylinder 46 from an outer
surface, the gas may flow into the second cylinder 46 from the
low-temperature side suction port 52. If necessary, a rotary disc
or the like for imparting a flu wheel effect is imparted to the
control mechanism 18.
[0060] Moreover, the rotary mechanism of the stirling system 10 has
been described with the rolling piston type, but the stirling
system 10 is not limited to the rolling piston type, and the
present invention is effective, even when a rotary mechanism of a
scroll type including a fixed scroll and a rocking scroll is used.
Furthermore, in addition to the rotary mechanism (the rolling
piston type) which achieves the purpose of the stirling system 10,
examples of similarly applicable candidates in principle include "a
swing rotor type" and "a multi-vane type", and include "a Wankel
type" as the case may be. Even if such type constitutes the
stirling system 10, the present invention is effective.
[0061] Furthermore, in the embodiment, the shape, the dimension and
the like of the stirling system 10 have been described, but the
stirling system 10 may be changed without departing from the scope
of the present invention. Needless to say, the present invention is
not limited to the above embodiment. Even if the present invention
is variously modified without departing from the scope of the
present invention, the present invention is effective.
* * * * *