U.S. patent application number 10/570132 was filed with the patent office on 2007-02-08 for loop type thermo siphon, stirling cooling chamber, and cooling apparatus.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. Invention is credited to Wei Chen.
Application Number | 20070028626 10/570132 |
Document ID | / |
Family ID | 34277682 |
Filed Date | 2007-02-08 |
United States Patent
Application |
20070028626 |
Kind Code |
A1 |
Chen; Wei |
February 8, 2007 |
Loop type thermo siphon, stirling cooling chamber, and cooling
apparatus
Abstract
A loop thermosyphon includes a closed circuit configured of an
evaporator, a condenser, a feed pope and a return pope, and the
evaporator is an assembly including a header pipe associated with
the feed pope, a header pipe associated with the return pipe, and a
plurality of aligned pipes. Each of the aligned popes is a
serpentine tube defined by a linear portion forming a plurality of
stages in vertically parallel layers, and a curved portion
connecting such linear portions together. The condenser is entirely
inclined relative to a bottom surface of a casing mounting the loop
thermosyphon such that the serpentine tube's linear portions have a
bottommost linear portion inclined in a direction allowing the
bottommost linear portion to be closer to the bottom surface of the
casing as the bottommost linear portion approaches the header pipe
associated with the return pipe.
Inventors: |
Chen; Wei; (Nara-Shi,
JP) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka-shi, Osaka
JP
545-8522
|
Family ID: |
34277682 |
Appl. No.: |
10/570132 |
Filed: |
August 12, 2004 |
PCT Filed: |
August 12, 2004 |
PCT NO: |
PCT/JP04/11600 |
371 Date: |
March 1, 2006 |
Current U.S.
Class: |
62/6 ;
165/104.21 |
Current CPC
Class: |
F25B 9/14 20130101; F25B
2500/01 20130101; F25D 2317/0682 20130101; F25B 25/00 20130101;
F28D 15/0266 20130101; F25D 11/00 20130101; F25B 23/006 20130101;
F28D 2015/0216 20130101 |
Class at
Publication: |
062/006 ;
165/104.21 |
International
Class: |
F25B 9/00 20060101
F25B009/00; F28D 15/00 20060101 F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 2, 2003 |
JP |
2003-309708 |
Jan 29, 2004 |
JP |
2004-020679 |
Claims
1. (canceled)
2. (canceled)
3. A Loop thermosyphon mounted at a casing of equipment having a
heat source, and employing a working fluid enclosed in a closed
circuit to transfer heat from said heat source, said closed circuit
including: an evaporator depriving said heat source of heat to
evaporate said working fluid; a condenser condensing said working
fluid evaporated at said evaporator; a feed pipe feeding to said
condenser said working fluid evaporated at said evaporator; and a
return pipe returning to said evaporator said working fluid
condensed at said condenser, wherein said condenser is an assembly
including a header pipe associated with said feed pipe, and
connected to said feed pipe to branch said working fluid introduced
thereinto, a header pipe associated with said return pipe, and
connected to said return pipe and joining together said working
fluid branched, and a plurality of aligned pipes extending in a
same direction and connecting said header pipes together at a
single side of said condenser, said aligned pipes are each a
serpentine tube having a linear portion extending in one direction
and forming a plurality of stages in layers, and a curved portion
connecting such linear portions together, and said condenser is
entirely inclined relative to a bottom surface of said casing
within a range larger than 0.degree. to at most 6.degree. such that
of said linear portions, a bottommost linear portion is inclined in
a direction allowing said bottommost linear portion to be closer to
said bottom surface as said bottommost linear portion approaches
said header pipe associated with said return pipe, so that
defective operation attributed to disposition is prevented.
4. The loop thermosyphon according to claim 3, wherein said
condenser is arranged to incline relative to said bottom surface of
said casing at an angle of 3.degree..
5. The loop thermosyphon according to claim 3, wherein: said header
pipe associated with said return pipe extends in a second direction
traversing said first direction; said return pipe is connected in a
vicinity of one end of said header pipe associated with said return
pipe and extending in said second direction; and said header pipe
associated with said return pipe is inclined in a direction
allowing said header pipe associated with said return pipe to be
closer to said bottom surface of said casing as said header pipe
associated with said return pipe extends toward said one end from
the other end positionally opposite said one end, so that defective
operation attributed to disposition is prevented.
6. A Stirling refrigerator having a Stirling refrigerating machine
mounted, wherein: said Stirling refrigerating machine includes the
loop thermosyphon of claim 3; and said evaporator is configured to
exchange heat with a heated portion of said Stirling refrigerating
machine.
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. A cooling apparatus having a Stirling refrigerating machine,
and a heat transfer cycle associated with a heated portion and
externally radiating hot generated by said Stirling refrigerating
machine at said heated portion, wherein: said heat transfer cycle
associated with said heated portion includes an evaporator
associated with said heated portion and attached to said Stirling
refrigerating machine at said heated portion and a condenser
associated with said heated portion and arranged to be higher in
level than said evaporator, with a vapor coolant pipe and a
condensate coolant pipe connecting said evaporator and said
condenser to form a coolant circulation circuit, said condenser is
formed of a plurality of condensation pipes and a fin, said
condensate coolant pipe includes a lateral pipe having closed
opposite ends and connected to said plurality of condensation pipes
at their respective ends, and a pair of vertical pipes connecting
said evaporator and said lateral pipe together, one of said
vertical pipes has an upper end connected to said lateral pipe at
one end and the other of said vertical pipes has an upper end
connected to said lateral pipe at the other end, the cooling
apparatus characterized in that said one vertical pipe has said
upper end thereof connected to said lateral pipe at a location
closer to said one end of said lateral pipe than said condensation
pipes are connected to said lateral pipe, and said other vertical
pipe has said upper end thereof connected to said lateral pipe at a
location closer to said other end of said lateral pipe than said
condensation pipes are connected to said lateral pipe.
12. The cooling apparatus according to claim 11, wherein said
vertical pipe has an inclined portion having a downward
gradient.
13. The cooling apparatus according to claim 12, wherein said
downward gradient is at least 5.degree. with reference to said
cooling apparatus placed in a horizontal position.
14. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates generally to loop
thermosyphons, Stirling refrigerators having the loop thermosyphon
mounted, and cooling apparatuses equipped with a Stirling
refrigerating machine.
BACKGROUND ART
[0002] Conventionally, heat radiation systems employing heat sinks,
heat pipes, thermosyphons and the like have been known as heat
radiation systems radiating heat generated from heat sources. For a
heat radiation system with a heat sink attached to a heat source,
the heat sink has a significant distribution in temperature. As
such, the remoter it is from the heat source, the less it
contributes to heat radiation. It thus has its limit in improving
heat radiation performance. In contrast, heat radiation systems
employing a heat pipe, a thermosyphon or the like employ a working
fluid to transfer heat generated at a heat source. As such, they
have a significantly higher ability to transfer heat than a heat
sink and can thus maintain high heat radiation performance.
[0003] A heat pipe is a capillarity driven heat transfer device
circulating a working fluid through a capillary action of a wick
arranged in a closed circuit. By contrast, a thermosyphon is a
gravity driven heat transfer device utilizing a difference in
density of a working fluid that is caused as the working fluid
evaporates and condenses. Note that a loop thermosyphon is a
thermosyphon configured to circulate a working fluid in a closed
circuit formed in a loop.
[0004] Initially as a first conventional example a typical loop
thermosyphon will be described. FIGS. 17A and 17B schematically
show the first conventional example of loop thermosyphon in
structure, as seen in front and side views, respectively.
[0005] As shown in the figures, a loop thermosyphon 100I includes
an evaporator 110 depriving a heat source of heat and a condenser
130I externally discharging heat. Evaporator 110 and condenser 130I
are connected by a feed pipe 120 and a return pipe 140, and
evaporator 110, feed pipe 120, condenser 130I and return pipe 140
together form a closed circuit. Note that condenser 130I is
disposed at a position higher than evaporator 110.
[0006] In evaporator 110 a working fluid deprives the heat source
of heat and thus evaporates, and ascends by a vapor pressure
difference between evaporator 110 and condenser 130I against
gravity through feed pipe 120 and enters condenser 130I. Condenser
130I cools and thus condenses the working fluid, which is in turn
pulled by gravity, and thus descends through return pipe 140 and
enters evaporator 110. Such convection of the working fluid
involving a change in phase as described above allows the heat
source to externally radiate heat.
[0007] Stirling refrigerators equipped with a loop thermosyphon
thus configured are disclosed for example in Japanese Patent
Laying-Open Nos. 2003-50073, 2001-33139 and 2003-302117 (Patent
Documents 1, 2 and 3).
[0008] As a second conventional example a cooling apparatus
equipped with a conventional Stirling refrigerating machine
described in Patent Document 3 will be described more specifically.
FIG. 20 is a side view schematically showing a configuration of the
cooling apparatus in the second conventional example. The figure
shows a cooling apparatus 50 including a heat transfer cycle 5
associated with a cold portion and extracting cold generated at
Stirling refrigerating machine 1, and a heat transfer cycle 4
associated with a heated portion and externally radiating hot.
Stirling refrigerating machine 1 includes a cold portion 3
absorbing heat to generate cold as an internally sealed working
medium (e.g., helium) expands, and a heated portion 2 generating
hot as the working medium expands.
[0009] Heat transfer cycle 5 associated with the cold portion is
generally a circulation circuit including a condenser 12 associated
with the cold portion and attached around and in contact with cold
portion 3, and an evaporator 15 associated with the cold portion
and connected to condenser 12 via a condensate coolant pipe 13 and
a vapor coolant pipe 14. This circuit has carbon dioxide,
hydrocarbon or the like sealed therein as a coolant to form a
thermosyphon therein. Evaporator 15 has a plurality of fins 16 each
in the form of a flat plate to exchange heat over an increased
area. Furthermore, to allow the coolant's evaporation and
condensation and resultant natural circulation to be utilized,
evaporator 15 is arranged to be lower than condenser 12. Below
condenser 15 is arranged a drain plate 17 to reserve drainage
condensed on and dropping from a surface of evaporator 15.
[0010] Heat transfer cycle 4 associated with the heated portion is
a thermosyphon employing water, hydrocarbon or a similar natural
coolant, and generally a circulation circuit including an
evaporator 6 associated with the heated portion and attached to
Stirling refrigerating machine 1 at heated portion 2, a condenser 8
associated with the heated portion and arranged to be higher than
evaporator 6 to condense the natural coolant, and a vapor coolant
pipe 7 and a condensate coolant pipe 11 connecting evaporator 6 and
condenser 8 together to circulate the coolant. The circuit has
water (including an aqueous solution), hydrocarbon or a similar
natural coolant sealed therein as the coolant. The use of water
(including the aqueous solution), hydrocarbon or the like as a
coolant can eliminate negative effect on environment, human body
and the like. Note that to allow the coolant's evaporation and
condensation and resultant natural circulation to be smoothly
provided, condensate coolant pipe 11 is connected to evaporator 6
at a topmost end. Condenser 8 has a plurality of fins 18 each in
the form of a flat plate attached thereto to exchange heat over an
increased area and behind condenser 8 is provided a pair of heat
radiating fans 19 operated to externally discharge heat.
[0011] FIG. 21 is a perspective view specifically showing a
structure of the heat transfer cycle associated with the heated
portion in the cooling apparatus described as the second
conventional example. With reference to the figure, heat transfer
cycle 4 will further more specifically be described in structure.
Evaporator 6 as a whole forms a ring, which is adapted to have a
structure formed of two semi-rings 6A and 6B joined together along
the ring's diameter to help to attach evaporator 6 to Stirling
refrigerating machine 1 at heated portion 2. Each semi-ring 6A, 6B
is an arc having opposite ends or surfaces closed. Semi-rings 6A
and 6B are arranged to surround heated portion 2 and joined
together vertically thereabove and therebelow, and have their
respective lower ends connected by a U-letter communication pipe 6C
for communication. Semi-rings 6A and 6B have their internal
coolant's condensate communicated through connection pipe 6C and
thus mixed together.
[0012] Vapor coolant pipe 7 is formed of two vertical pipes 7A and
7B connected to semi-rings 6A and 6B, respectively, and a lateral
pipe 7C (also referred to as a header pipe) connected to vertical
pipes 7A and 7B. Vertical pipes 7A and 7B are connected to
semi-rings 6A and 6B at their respective outer circumferential,
upper ends, respectively, and lateral pipe 7C at a bottommost
portion vertically. Lateral pipe 7C has longitudinally opposite end
surfaces closed and is arranged in a direction orthogonal to an
axis of Stirling refrigerating machine 1 and horizontally.
[0013] Condensate coolant pipe 11 is similar in structure to pipe
7, although to form a thermosyphon, vapor coolant pipe 7 has
lateral pipe 7C arranged at a position higher than a lateral pipe
111C of condensate coolant pipe 11, and to efficiently operate the
thermosyphon, the vertical and lateral pipes are both relatively
larger in diameter for vapor coolant pipe 7 than condensate coolant
pipe 11.
[0014] Condenser 8 is formed of six serpentine tubes 8A-8F arranged
in parallel in the longitudinal direction of lateral pipes 7C and
11C, or horizontally. Serpentine tubes 8A-8F each have one end
connected to lateral pipe 7C and the other end to lateral pipe 11C
and together connect lateral pipes 7C and 11C together equally in
their longitudinal direction. Furthermore, the plurality of fins 18
are arranged at a linear portion of serpentine tubes 8A-8F in
parallel and thermally coupled therewith.
[0015] Heat transfer cycle 4 operates as described hereinafter.
Heated portion 2 generates heat which is in turn transferred from
around heated portion 2 to evaporator 6 and evaporates the coolant
in semi-rings 6A and 6B. The coolant evaporated in semi-ring 6A and
that evaporated in semi-ring 6B ascend through the vapor coolant
pipe 7 vertical pipes 7A and 7B, respectively, and are joined in
lateral pipe 7C and then branched to flow into serpentine tubes
8A-8F. Thus the coolant's vapor passes through condenser 8 arranged
at a position higher than evaporator 6 and exchanges heat via fin
18 with the surrounding ambient and thus becomes a condensate.
[0016] The condensate (or that having gas mixed together) conflows
in condensate coolant pipe 11 at lateral pipe 11C and furthermore
branches to vertical pipes 11A and 11B and flows downward to return
to evaporator 6 and is again evaporated by heat of heated portion
2. By thus utilizing latent heat in the coolant's evaporation and
condensation a significantly larger amount of heat is transferred
than by utilizing exchange heat through sensible heat. This allows
heat to be exchanged significantly effectively. Furthermore in the
present invention, as described above, a difference in level
between condenser 8 and evaporator 6 vertically arranged and a
difference in specific gravity between gas and liquid provide a
difference in pressure providing a driving force to circulate the
coolant. This can eliminate the necessity of employing a pump or a
similar external force to circulate the coolant and thus save
energy.
[0017] Patent Document 1: Japanese Patent Laying-Open No.
2003-050073
[0018] Patent Document 2: Japanese Patent Laying-Open No.
2001-033139
[0019] Patent Document 3: Japanese Patent Laying-Open No.
2003-302117
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0020] The above described, first conventional example's loop
thermosyphon 100I often has condenser 130I with a variety of pipes
and radiating fins combined together in an assembly and thus
unitized and thus fabricated. More specifically, it is fabricated
as an assembly formed of a header pipe 131 associated with a feed
pipe and branching a working fluid introduced through a feed pipe
120, a header pipe 132 associated with a return pipe and allowing
the branched working fluid to rejoin, a plurality of aligned pipes
133 extending in the same direction and connecting header pipes 131
and 132 together (see FIG. 18), and a radiating fin (not shown)
assembled in contact with the plurality of aligned pipes 133.
[0021] Typically, as shown in FIG. 18, the plurality of aligned
pipes 133 each have linear portions 134a-134d extending linearly in
one direction and arranged in parallel in layers to form a
plurality of vertically arranged stages (in FIG. 18, four stages),
and curved portions 135a-135c connecting linear portions 134a-134d
together. More specifically, each aligned pipe 133 is formed to be
a serpentine tube as shown in FIG. 18. The plurality of linear
portions 134a-134d are arranged in parallel layers mainly in order
to facilitate fabrication and also ensures a maximum heat transfer
area with a smaller space.
[0022] Condenser 130I implemented by the assembly thus configured
is arranged in equipment (e.g., a Stirling refrigerator) having
loop thermosyphon 100I mounted, at a casing 300 above a bottom
surface 301, as shown in FIG. 17. Note that condenser 130I
implemented by the assembly is arranged parallel to bottom surface
301.
[0023] When the equipment having loop thermosyphon 100I mounted has
casing 300 with bottom surface 301 parallel to a surface on which
it is disposed, or a floor surface 401, as shown in FIG. 18,
condenser 130I has aligned pipe 133 with linear portions 134a-134d
also parallel to floor surface 401. In that case, the working fluid
condensed and thus liquefied in condenser 130I at aligned pipe 133
smoothly flows through aligned pipe 133 and is delivered through
header pipe 132 and return pipe 140 to evaporator 110. Note that in
the figure the working fluid flows in a direction indicated by an
arrow 500.
[0024] If the equipment is disposed such that the casing has the
bottom surface parallel to the floor surface, it does not cause a
particular problem. If the casing has the bottom surface inclined
relative to a horizontal floor surface or a floor surface itself is
inclined and the casing is arranged parallel to the inclined floor
surface, however, the loop thermosyphon will also be inclined
relative to horizon and the working fluid's flow can be
significantly affected thereby.
[0025] For example, if the equipment has casing 300 inclined
relative to a horizontal floor surface 401 by an angle
.alpha..sub.0, as shown in FIG. 19, then condenser 130I, having
aligned pipe 133 with linear portions 134a-134d also parallel to
the casing 300 bottom surface 301, will be inclined relative to the
horizontal plane by angle .alpha..sub.0. Note that the shown
condition shows that the equipment's casing 300 inclined and thus
arranged so that the bottommost stage or linear portion 134d has an
end adjacent to curved portion 135c lower in level than that
adjacent to header pipe 132 associated with the return pipe.
[0026] If in that condition condenser 130I is arranged, the working
fluid condensed and thus liquefied in condenser 130I at the
bottommost stage or linear portion 134d is pulled by gravity and
thus flows back and will stay in the bottommost stage or linear
portion 134d closer to curved portion 135c. The condensed working
fluid 502 will not flow into header pipe 132 associated with the
return pipe, and as the equipment operates, working fluid 502 is
gradually accumulated and finally will have a level 503 raised to
close aligned pipe 133.
[0027] In such condition unless aligned pipe 133 has a considerably
increased pressure at a portion closer to header pipe 131
associated with the feed pipe the working fluid will be prevented
from flowing. The working fluid circulates in an unexpected
operation, and the heat generated at the heat source cannot be
radiated sufficiently. As a result, the loop thermosyphon operates
defectively, and in the worst case, the main body of the equipment
having the loop thermosyphon mounted may fails.
[0028] Thus the first conventional example's loop thermosyphon can
provide a defective operation depending on how it is arranged, and
this has been a significantly serious issue to be addressed.
[0029] Furthermore the second conventional example's cooling
apparatus 50 including Stirling refrigerating machine 1 is itself
assembled independently and thereafter mounted in a refrigerator
(not shown) and thus shipped as a product. Note that cooling
apparatus 50 is incorporated so that when the refrigerator is
disposed at a horizontal place lateral pipes 7C and 11C are
horizontal.
[0030] However, if the second conventional example's cooling
apparatus is thus incorporated, it cannot be expected that the user
ensures that the refrigerator is disposed at a horizontal place,
and in reality the refrigerator can be placed at a slanting place.
In that case, as shown in FIG. 22, the entirety of the system will
be inclined relative to the horizontal plane, and condensate
coolant pipe 11 will have a condensate coolant 20 staying in a
lateral pipe 11C at a portion lower than an upper end of a vertical
pipe (in FIG. 22, 11B) lower in the direction of gravity. As a
result, the coolant circulates in a reduced amount resulting in
impaired heat radiation efficiency.
[0031] Accordingly the present invention contemplates a loop
thermosyphon capable of preventing defective operation regardless
of disposition, and a Stirling refrigerator equipped therewith.
[0032] The present invention also contemplates a cooling apparatus
capable of reliably circulating a coolant in a heat transfer cycle
associated with a heated portion of a Stirling refrigerating
machine if the apparatus is inclined.
MEANS FOR SOLVING THE PROBLEMS
[0033] A loop thermosyphon in a first aspect of the present
invention is mounted at a casing of equipment having a heat source,
and employs a working fluid enclosed in a closed circuit to
externally radiate heat from the heat source. Note that a "loop
thermosyphon mounted at a casing" as referred to herein includes a
loop thermosyphon entirely accommodated in the casing and a loop
thermosyphon partially accommodated in the casing and partially
exposed. The closed circuit includes: an evaporator depriving the
heat source of heat to evaporate the working fluid; a condenser
condensing the working fluid evaporated at the evaporator; a feed
pipe feeding to the condenser the working fluid evaporated at the
evaporator; and a return pipe returning to the evaporator the
working fluid condensed at the condenser. The condenser has a
serpentine tube having a linear portion extending in one direction
and forming a plurality of stages in layers, and a curved portion
connecting such linear portions together, and the serpentine tube
has a bottommost one of the linear portions inclined in a direction
allowing the bottommost linear portion to be closer to a bottom
surface of the casing as the bottommost linear portion approaches
the return pipe.
[0034] This can reduce the possibility that the working fluid
condensed and liquefied will stay in the serpentine tube, and the
loop thermosyphon's defective operation attributed to disposition
can be reduced.
[0035] A loop thermosyphon in a second aspect of the present
invention is mounted at a casing of equipment having a heat source,
and employs a working fluid enclosed in a closed circuit to
externally radiate heat from the heat source. The closed circuit
includes: an evaporator depriving the heat source of heat to
evaporate the working fluid; a condenser condensing the working
fluid evaporated at the evaporator; a feed pipe feeding to the
condenser the working fluid evaporated at the evaporator; and a
return pipe returning to the evaporator the working fluid condensed
at the condenser. The condenser is an assembly including a header
pipe associated with the feed pipe, and connected to the feed pipe
to branch the working fluid introduced thereinto, a header pipe
associated with the return pipe, and connected to the return pipe
and joining together the working fluid branched, and a plurality of
aligned pipes extending in a same direction and connecting the
header pipes together. The aligned pipes are each a serpentine tube
having a linear portion extending in one direction and forming a
plurality of stages in layers, and a curved portion connecting such
linear portions together. The assembly or condenser is entirely
inclined relative to a bottom surface of the casing such that of
the linear portions, a bottommost linear portion is inclined in a
direction allowing the bottommost linear portion to be closer to
the bottom surface as the bottommost linear portion approaches the
header pipe associated with the return pipe.
[0036] If the condenser is fabricated to be a unit such that the
serpentine tube has the linear portion arranged in vertically
parallel layers, the possibility that the working fluid condensed
and liquefied will stay in the serpentine tube can nonetheless be
reduced. The loop thermosyphon's defective operation attributed to
disposition can thus be reduced.
[0037] Preferably in the loop thermosyphon in the second aspect of
the present invention the condenser is arranged to incline relative
to the bottom surface of the casing at an angle larger than
0.degree. and at most 6.degree..
[0038] The condenser that is previously inclined to satisfy such
condition can significantly prevent the loop thermosyphon's
defective operation attributed to disposition.
[0039] Preferably in the loop thermosyphon in the second aspect of
the present invention the header pipe associated with the return
pipe extends in a second direction traversing the first direction,
the return pipe is connected in a vicinity of one end of the header
pipe associated with the return pipe and extending in the second
direction, and the header pipe associated with the return pipe is
inclined in a direction allowing the header pipe associated with
the return pipe to be closer to the bottom surface of the casing as
the header pipe associated with the return pipe extends toward the
one end from the other end positionally opposite the one end.
[0040] This can reduce the possibility that the working fluid
condensed and liquefied will stay in the header pipe associated
with the return pipe. The loop thermosyphon's defective operation
attributed to disposition can thus be reduced.
[0041] A loop thermosyphon in a third aspect of the present
invention is mounted at a casing of equipment having a heat source,
and employs a working fluid enclosed in a closed circuit to
externally radiate heat from the heat source. The closed circuit
includes: an evaporator depriving the heat source of heat to
evaporate the working fluid; a condenser condensing the working
fluid evaporated at the evaporator; a feed pipe feeding to the
condenser the working fluid evaporated at the evaporator; and a
return pipe returning to the evaporator the working fluid condensed
at the condenser. The condenser is an assembly including a header
pipe associated with the feed pipe, and connected to the feed pipe
to branch the working fluid introduced thereinto, a header pipe
associated with the return pipe, and connected to the return pipe
and joining together the working fluid branched, and a plurality of
aligned pipes extending in a same direction and connecting the
header pipes together. The header pipe associated with the return
pipe extends in one direction. The return pipe is connected in a
vicinity of one end of the header pipe associated with the return
pipe and extending in the one direction. The header pipe associated
with the return pipe is inclined in a direction allowing the header
pipe associated with the return pipe to be closer to a bottom
surface of the casing as the header pipe associated with the return
pipe extends toward the one end from the other end positionally
opposite the one end.
[0042] This can reduce the possibility that the working fluid
condensed and liquefied will stay in the header pipe associated
with the return pipe. The loop thermosyphon's defective operation
attributed to disposition can thus be reduced.
[0043] A loop thermosyphon in a fourth aspect of the present
invention is mounted at a casing of equipment having a heat source,
and employs a working fluid enclosed in a closed circuit to
externally radiate heat from the heat source. The closed circuit
includes: an evaporator depriving the heat source of heat to
evaporate the working fluid; a condenser condensing the working
fluid evaporated at the evaporator; a feed pipe feeding to the
condenser the working fluid evaporated at the evaporator; and a
return pipe returning to the evaporator the working fluid condensed
at the condenser. The condenser is an assembly including a header
pipe associated with the feed pipe, and connected to the feed pipe
to branch the working fluid introduced thereinto, a header pipe
associated with the return pipe, and connected to the return pipe
and joining together the working fluid branched, and a plurality of
linear tubes arranged in parallel and connecting the header pipes
together. The linear tubes are each inclined in a direction
allowing each the linear tube to be closer to a bottom surface of
the casing as each the linear tube approaches the header pipe
associated with the return pipe.
[0044] If a condenser is employed that has a linear tube, rather
than a serpentine tube, connecting together header pipes associated
with feed and return pipes, respectively, the condenser will not
have a working fluid convected in the pipe, and the loop
thermosyphon's defective operation attributed to disposition can
thus be reduced.
[0045] The present Stirling refrigerator is a Stirling refrigerator
having a Stirling refrigerating machine mounted. The Stirling
refrigerating machine includes any of the loop thermosyphons in the
first to fourth aspects of the present invention and the loop
thermosyphon has an evaporator configured to exchange heat with a
heated portion of the Stirling refrigerating machine.
[0046] The Stirling refrigerator thus configured is not affected in
performance by how a casing is disposed.
[0047] A cooling apparatus in a first aspect of the present
invention has a heat transfer cycle associated with a cold portion
and extracting cold generated by a Stirling refrigerating machine
at the cold portion, and a heat transfer cycle associated with a
heated portion and externally radiating hot generated by the
Stirling refrigerating machine at the heated portion. The heat
transfer cycle associated with the heated portion includes an
evaporator associated with the heated portion and attached to the
Stirling refrigerating machine at the heated portion and a
condenser associated with the heated portion and arranged to be
higher in level than the evaporator, with a vapor coolant pipe and
a condensate coolant pipe connecting the evaporator and the
condenser to form a coolant circulation circuit, and the condensate
coolant pipe includes a lateral pipe having opposite ends closed
and connected to the condenser and a pair of vertical pipes
vertically connecting the evaporator and the lateral pipe together,
the pair of vertical pipes having one and the other, upper ends
connected to the lateral pipe at one and the other ends,
respectively. If the cooling apparatus is inclined, the heat
transfer cycle associated with the heated portion will not have the
coolant's condensate staying in the lateral pipe.
[0048] In the cooling apparatus in the first aspect of the present
invention the vertical pipe has an upper end with a lateral pipe
connected thereto and a lower end with the evaporator associated
with the heated portion connected thereto, however, the
connections' ports do riot necessarily, positionally match with
each other as seen horizontally. Accordingly, the vertical pipe is
provided with an inclined portion having a downward gradient. In
general, a refrigerator is installed at a place having an
inclination within 5.degree. for safety, and providing the vertical
pipe with an inclined portion having a downward gradient of at
least 5.degree. with reference to the cooling apparatus placed in a
horizontal position allows the downward gradient to be maintained
if the cooling apparatus is inclined, and the coolant's condensate
can be prevented from clogging.
[0049] A cooling apparatus in a second aspect of the present
invention has a heat transfer cycle associated with a cold portion
and extracting cold generated by a Stirling refrigerating machine
at the cold portion, and a heat transfer cycle associated with a
heated portion and externally radiating hot generated by the
Stirling refrigerating machine at the heated portion. The heat
transfer cycle associated with the heated portion includes an
evaporator associated with the heated portion and attached to the
Stirling refrigerating machine at the heated portion and a
condenser associated with the heated portion and arranged to be
higher in level than the evaporator, with a vapor coolant pipe and
a condensate coolant pipe connecting the evaporator and the
condenser to form a coolant circulation circuit. The condensate
coolant pipe includes a lateral pipe having opposite ends closed
and connected to the condenser and a pair of vertical pipes
vertically connecting the evaporator and the lateral pipe together,
and the vapor coolant pipe includes a lateral pipe having opposite
ends closed and connected to the condenser and a pair of vertical
pipes vertically connecting the evaporator and the lateral pipe
together. The lateral pipe of the vapor coolant pipe is arranged to
be higher in level than the lateral pipe of the condenser coolant
pipe and a degassing charge pipe is attached to the vapor coolant
pipe at the lateral pipe. The charge pipe attached at such a high
position can prevent water from being sucked in vacuuming and also
contribute to improved efficiency in vacuuming.
EFFECT OF THE INVENTION
[0050] The loop thermosyphon in the first to fourth aspects of the
present invention can be prevented from defective operation
regardless of disposition. Furthermore the Stirling refrigerator of
the present invention can exhibit high performance regardless of
how the casing is disposed.
[0051] Furthermore in the cooling apparatus in the first and second
aspects of the present invention as a Stirling refrigerating
machine is driven a heated portion generates heat, which is
transferred and externally radiated by a thermosyphon utilized in a
heat transfer cycle associated with the heated portion and having a
condensate coolant pipe passing the coolant's condensate naturally
downward toward an evaporator associated with the heated portion,
that is configured of a lateral pipe having opposite ends closed
and disposed at an outlet of a condenser associated with the heated
portion and a pair of vertical pipes vertically connecting together
the lateral pipe and the evaporator associated with the heated
portion, with each vertical pipe having an upper end connected to
the lateral pipe at one and the other ends, respectively. If the
cooling apparatus is inclined, the coolant's condensate does not
stay in the lateral pipe of the heat transfer cycle associated with
the heated portion. The cycle can thus circulate the coolant
reliably.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 is a schematic, perspective view of a structure of
the present loop thermosyphon in the first embodiment
installed.
[0053] FIG. 2 schematically shows a configuration of a condenser of
the FIG. 1 loop thermosyphon.
[0054] FIGS. 3A and 3B schematically show how the condenser of the
present loop thermosyphon in the first embodiment is installed,
with the loop thermosyphon seen in front and side views,
respectively.
[0055] FIG. 4 shows how a working fluid flows in the first
embodiment when the condenser inclines relatives to a horizontal
plane.
[0056] FIG. 5 shows how a working fluid flows in the first
embodiment when the condenser inclines relatives to a horizontal
plane.
[0057] FIGS. 6A and 6B schematically show how the condenser of the
present loop thermosyphon in a second embodiment is installed, with
the loop thermosyphon seen in front and side views,
respectively.
[0058] FIGS. 7A and 7B schematically show how the condenser of the
present loop thermosyphon in a third embodiment is installed, with
the loop thermosyphon seen in front and side views,
respectively.
[0059] FIG. 8 schematically shows a configuration of a condenser of
the present loop thermosyphon in a fourth embodiment.
[0060] FIG. 9 schematically shows how the present loop thermosyphon
in the fourth embodiment is installed, as seen in a side view.
[0061] FIGS. 10-13 schematically show configurations of the present
loop thermosyphon in fifth to eighth embodiments, respectively.
[0062] FIG. 14 is a schematic cross section of a structure of the
present Stirling refrigerator in a ninth embodiment.
[0063] FIG. 15 is a perspective view specifically showing a
structure of a heat transfer cycle associated with a heated portion
in a tenth embodiment of the present invention.
[0064] FIGS. 16A and 16B are front and side views, respectively, of
the heat transfer cycle associated with the heated portion in the
tenth embodiment.
[0065] FIGS. 17A and 17B schematically show a structure of a loop
thermosyphon in a first conventional example, as seen in front and
side views, respectively.
[0066] FIG. 18 schematically shows a structure of a condenser of
the loop thermosyphon in the first conventional example, showing
how a working fluid flows with the condenser disposed
horizontally.
[0067] FIG. 19 shows how the working fluid flows with the FIG. 18
condenser inclined relative to a horizontal plane.
[0068] FIG. 20 is a side view schematically showing a structure of
a cooling apparatus in a second conventional example.
[0069] FIG. 21 is a perspective view specifically showing a
structure of a heat transfer cycle associated with a heated portion
of the cooling apparatus of the second conventional example.
[0070] FIG. 22 is a front view of a main portion of the heat
transfer cycle associated with the heated portion with the FIG. 20,
second conventional example's cooling apparatus inclined.
DESCRIPTION OF THE REFERENCE SIGNS
[0071] 1: Stirling refrigerating machine, 2: heated portion, 3:
cold portion, 4: heat transfer cycle associated with the heated
portion, 5: heat transfer cycle associated with the cold portion,
6: evaporator associated with the heated portion, 6A, 6B:
semi-ring, 7, 14: vapor coolant pipe, 7A, 7B: vertical pipe, 7C:
lateral pipe, 8: condenser associated with the heated portion,
8A-8F: serpentine tube, 11, 13,: condensate coolant pipe, 11A, 11B:
vertical pipe, 11Aa, 11Ba: inclined portion, 11C: lateral pipe, 12:
condenser associated with the cold portion, 15: evaporator
associated with the cold portion, 16, 18: fin in the form of a flat
plate, 17: drain plate, 19: heat radiating fan, 20: coolant's
condensate, 21: charge pipe, 50: cooling apparatus, 100, 100A-100I:
loop thermosyphon, 110: evaporator, 112: inner circumferential
surface, 120: feed pipe, 130, 130A-130I: condenser, 131: header
pipe associated with feed pipe, 132: header pipe associated with
return pipe, 133: aligned pipe, 134a-134e: linear portion,
135a-135d: curved portion, 136: radiating fin, 140: return pipe,
200: Stirling refrigerating machine, 202: pressure chamber, 204
heated portion, 206: cold portion, 250: supporting platform, 252:
bottom plate, 254a-254c: support, 300: casing, 301: bottom surface,
401: floor surface, 500: direction in which working fluid flows,
502: liquefied working fluid, 503: surface of liquid, 1000:
Stirling refrigerator, 1020: heat transfer system associated with
cold portion, 1023: cold duct, 1024: duct, 1025: air blowing fan,
1026: fan associated with freezer section, 1027: fan associated
with chiller section, 1028: freezer section. 1029: chiller
section
BEST MODES FOR CARRYING OUT THE INVENTION
[0072] Hereinafter the present invention in embodiments will be
described with reference to the drawings.
First Embodiment
[0073] Initially reference will be made to FIG. 1 to describe a
loop thermosyphon in the present embodiment and a structure of a
Stirling refrigerating machine installed with the loop thermosyphon
attached thereto.
[0074] As shown in the figure, a Stirling refrigerating machine 200
is placed on a supporting platform 250 and supported by supports
254a, 254b provided on platform 250 at a bottom plate 252.
Furthermore, a loop thermosyphon 100A is also placed on platform
250 and supported thereon by support 254a, 254c provided at a
bottom plate 252. Stirling refrigerating machine 200 and loop
thermosyphon 100A supported by platform 250 are disposed in a
casing of prescribed equipment (e.g., a refrigerator). Note that
platform 250 has bottom plate 252 parallel to a bottom surface of
the casing of the equipment.
[0075] Stirling refrigerating machine 200 is structured and
operates, as described hereinafter.
[0076] As shown in FIG. 1, Stirling refrigerating machine 200
includes a pressure chamber 202 provided therein with a cylinder
having a piston and a displacer fitted and thus attached thereto.
The cylinder is filled with helium or a similar working medium. The
cylinder has an internal space sectioned by the piston and the
displacer to provide a compression section and an expansion
section. The compression section is surrounded by a heated portion
204 and the expansion section is surrounded by a cold portion
206.
[0077] The piston fitted in the cylinder is driven by a linear
actuator to reciprocate in the cylinder. As the piston reciprocates
and pressure accordingly varies, the displacer reciprocates in the
cylinder with a constant phase difference from the piston's
reciprocation. As the piston and the displacer reciprocate, an
inverted Stirling cycle is implemented in the cylinder. Thus heated
portion 204 surrounding the compression section rises in
temperature and cold portion 206 surrounding the expansion section
is cooled to cryogenic temperature.
[0078] Loop thermosyphon 100A has a structure and operates as
described hereinafter.
[0079] As shown in FIG. 1, loop thermosyphon 100A includes an
evaporator 110 and a condenser 130A. Evaporator 110 is arranged in
contact with heated portion 204 of Stirling refrigerating machine
200 to deprive heated portion 204 of heat to evaporate a working
fluid introduced in evaporator 110. Condenser 130A is arranged at a
position higher than evaporator 110 to condense the working fluid
evaporated at evaporator 110. Evaporator 110 and condenser 130A are
connected by a feed pipe 120 and a return pipe 140 to together form
a closed circuit. Note that in loop thermosyphon 100A as shown in
the figure a heat source, or heated portion 204, has a cylindrical
geometry. Accordingly, evaporator 110 is formed of two arcuate
components.
[0080] With reference to FIGS. 1 and 2, condenser 130A is formed of
a header pipe 131 associated with the feed pipe, a header pipe 132
associated with the return pipe, a plurality of aligned pipes 133
connecting headers 131 and 132, and a radiating fin 136 provided in
contact with aligned pipes 133, assembled together to be a
unit.
[0081] Header pipe 131 is a distributor connected to feed pipe 120
to branch the working fluid introduced. In contrast, header pipe
132 is connected to return pipe 140 to collect pipes to join
branches of the working fluid together.
[0082] As shown in FIG. 2, aligned pipe 133 is each defined by
linear portions 134a-134d (in four stages for condenser 130A in the
present embodiment) linearly extending in a first direction (in the
figure, a direction A), and curved portions 135a-135c connecting
linear portions 134a-134d. Linear portions 134a-134d are arranged,
one on another, vertically in parallel. Curved portions 135a-135c
connect linear portions 134a-134d at their respective ends
together. More specifically, condenser 130A is configured of
aligned pipes 133 configured of laterally arranged serpentine
tubes. The plurality of aligned pipes 133 at linear portions
134a-134d have a plurality of radiating fins 136 assembled
thereto.
[0083] In evaporator 110 the working fluid deprives heated portion
204 of Stirling refrigerating machine 200 of heat and thus
evaporates, and ascends by a vapor pressure difference between
evaporator 110 and condenser 130A against gravity through feed pipe
120 and enters condenser 130A. Condenser 130A cools and thus
condenses the working fluid, which is in turn pulled by gravity,
and thus descends through return pipe 140 and enters evaporator
110. Such convection of the working fluid involving a change in
phase as described above allows heated portion 204 to externally
radiate heat.
[0084] In the present embodiment loop thermosyphon 100A has
condenser 130A arranged as described hereinafter.
[0085] As shown in FIGS. 3A and 3B the present embodiment loop
thermosyphon 100A has condenser 130A arranged to incline relative
to bottom surface 301 of casing 300 of a refrigerator or similar
equipment. More specifically, condenser 130A formed of an assembly
is arranged to incline by an angle .theta..sub.1 so that an end of
condenser 130A that is closer to header pipe 132 is closer to
bottom surface 301 than that of condenser 130A farther away from
header pipe 132 is
[0086] More specifically, condenser 130A is arranged to entirely
incline by angle .theta..sub.1 to have aligned serpentine tube 133
with the bottommost linear portion 134d inclined to be closer to
bottom surface 301 as the serpentine tube approaches header pipe
132. Condenser 130A is inclined relative to bottom surface 301 by
angle .theta..sub.1 preferably of larger than 0.degree. and at most
6.degree., more preferably approximately 3.degree.. This can be
done for example by adjusting support 254c of supporting platform
250 in height (see FIG. 1).
[0087] Thus arranging condenser 130A to incline relative to bottom
surface 301 of casing 300 by angle .theta..sub.1 allows loop
thermosyphon 100A to reliably operate regardless of how casing 300
is disposed, for the following reasons:
[0088] Initially, if casing 300 has bottom surface 301 parallel to
a horizontal floor surface, then condenser 130A, previously
arranged to incline relative to bottom surface 301 by angle
.theta..sub.1, will also be arranged to incline relative to a
horizontal plane by angle .theta..sub.1.
[0089] In condenser 130A aligned pipe 133 passes the working fluid,
which is condensed and liquefied in the bottommost stage's linear
portion 134d, and pulled by gravity to flow through the inclined
linear portion 134d toward header pipe 132 and thus flow out of
aligned pipes 133. Consequently, aligned pipe 133 will not have the
working fluid staying therein. Thus the working fluid can smoothly
flow and loop thermosyphon 100A can reliably operate.
[0090] Hereinafter will be considered four cases with casing 300
having bottom surface 301 inclined relative to a horizontal floor
surface.
[0091] In a first case, with reference to FIG. 3B, equipment has
casing 300 inclined in a direction B. In that case, condenser 130A
after installation will have an inclination of an angle larger than
angle .theta..sub.1 relative to the horizontal plane.
[0092] As has been described above, the working fluid flowing in
condenser 130A through aligned pipe 133 is condensed and liquefied
mainly at the bottommost linear portion 134d, and pulled by gravity
to flow through the inclined linear portion 134d toward header pipe
132 and flows out of aligned pipes 133. As such, aligned pipe 133
will not have the working fluid staying therein. As a result, the
working fluid can smoothly flow and loop thermosyphon 100A can
reliably operate.
[0093] If condenser 130A is arranged to incline by an angle larger
than a prescribed angle, however, and the surrounding temperature
or the like varies, aligned pipe 133 occasionally has the working
fluid condensed and liquefied not only at the bottommost linear
portion 134d but also linear portion 134c immediately overlying
linear portion 134d. In that case, the condensed working fluid may
stay in a vicinity of curved portion 135b adjacent to linear
portion 134c and thus close aligned pipe 133. Such phenomenon
occurs at a critical angle of approximately 6.degree., as confirmed
by the inventor, although it slightly varies depending on how
condenser 130A is designed in dimension or the like.
[0094] Typically, however, it is hardly conceivable that equipment
is arranged on a floor surface having an inclination of 3.degree.
or larger and it is also hardly conceivable that the equipment's
casing is arranged to incline relative to a horizontal floor
surface by 3.degree. or larger, and inclination or angle
.theta..sub.1 set to be approximately 3.degree. relative to bottom
surface 301 of condenser 130A would substantially completely
prevent such a situation as described above. Thus in most cases
loop thermosyphon 100A can reliably operate.
[0095] In a second case, with reference to FIG. 3B, equipment has
casing 300 inclined in a direction C by an angle .alpha..sub.1,
wherein .alpha..sub.1<.theta..sub.1. With casing 300 thus
inclined, condenser 130A after it is arranged will incline by an
angle .theta..sub.1-.alpha..sub.1 relative to a horizontal
plane.
[0096] As has been described above, the working fluid flowing in
condenser 130A through aligned pipe 133 is condensed and liquefied
mainly at the bottommost linear portion 134d. However, condenser
130A is inclined relative to the horizontal plane by angle
.theta..sub.1-.alpha..sub.1. Accordingly the working fluid
liquefied in the bottommost linear portion 134d flows through
linear portion 134d toward header pipe 132 and flows out of aligned
pipes 133. As such, aligned pipe 133 will not have the working
fluid staying therein. As a result, the working fluid can smoothly
flow and loop thermosyphon 100A can reliably operate.
[0097] In a third case, with reference to FIG. 3B, equipment has
casing 300 inclined in a direction C by an angle .alpha..sub.2,
wherein .alpha..sub.2=.theta..sub.1. With casing 300 thus inclined,
condenser 130A after it is disposed will be arranged
horizontally.
[0098] As has been described above, the working fluid flowing in
condenser 130A through aligned pipe 133 is condensed and liquefied
mainly at the bottommost linear portion 134d. In that case, with
the bottommost linear portion 134d horizontally disposed, the
convection of the working fluid caused in aligned pipe 133 allows
the liquefied working fluid to flow toward header pipe 132 and flow
out of aligned pipe 133. As such, aligned pipe 133 will not have
the working fluid staying therein. As a result, the working fluid
can smoothly flow and loop thermosyphon 100A can reliably
operate.
[0099] In a fourth case, with reference to FIG. 3B, equipment has
casing 300 inclined in direction C by an angle .alpha..sub.3,
wherein .alpha..sub.3>.theta..sub.1. With casing 300 thus
inclined, condenser 130A after it is arranged will incline by an
angle .alpha..sub.3-.theta..sub.1 relative to the horizontal
plane.
[0100] As has been described above, the working fluid flowing in
condenser 130A through aligned pipe 133 is condensed and liquefied
mainly at the bottommost linear portion 134d. As shown in FIG. 5,
the working fluid liquefied in linear portion 134d is pulled by
gravity to flow through linear portion 134d to move away from
header pipe 132. As a result, the liquefied working fluid 502 will
stay in the bottommost linear portion 134d closer to curved portion
135c.
[0101] However, with condenser 130A previously arranged to incline
relative to bottom surface 301 of casing 300, there is a smaller
possibility that working fluid 502 staying in aligned pipe 133 has
a level 503 closing aligned pipe 133 than when condenser 130A is
arranged parallel to bottom surface 301 of casing 300. More
specifically, as shown in FIG. 5, as long as aligned pipe 133 at a
connection of the bottommost linear portion 134d and curved portion
135d has an upper portion (indicated in FIG. 5 by a point D) upper
than a lower portion of the connection of the bottommost linear
portion 134d and header pipe 132, working fluid 502 flowing back
and thus staying will not close aligned pipe 133. As a result, the
working fluid is not prevented from flowing and can flow
smoothly.
[0102] It should be noted, however, that if condenser 130A is
further inclined, i.e., if aligned pipe 133 at the connection of
the bottommost linear portion 134d and curved portion 135d has an
upper portion (indicated in FIG. 5 by point D) upper than a lower
portion of the connection of the bottommost linear portion 134d and
header pipe 132, then aligned pipe 133 will be closed by the
liquefied working fluid, and the working fluid will be prevented
from flowing. Typically, however, it is also hardly conceivable
that equipment has a casing arranged with an inclination of
3.degree. or larger relative to a horizontal floor surface, and
inclination or angle .theta..sub.1 set to be approximately
3.degree. relative to bottom surface 301 of condenser 130A would
substantially completely prevent such a situation as described
above. Thus in most cases loop thermosyphon 100A can reliably
operate.
[0103] Note that while in the above description a casing is
arranged to incline relative to a horizontal floor surface by way
of example, the above also similarly applies if the casing is
arranged parallel to an originally inclined floor surface.
[0104] Thus, as described in the present embodiment, previously
arranging a condenser formed of an assembly to incline in a
prescribed direction by a prescribed angle can prevent a loop
thermosyphon from defective operation attributed to disposition.
The loop thermosyphon can reliably operate, and as a result the
Stirling refrigerating machine can be protected against damage
attributed to unexpected defective operation, and can also have a
heated portion reliably cooled and hence operate significantly
efficiently.
Second Embodiment
[0105] The present embodiment provides a loop thermosyphon 100B
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first embodiment. Accordingly, the components similar to
those of the first embodiment are shown in the figures with
identical reference characters.
[0106] As shown in FIGS. 6A and 6B, the present embodiment provides
loop thermosyphon 100B with a condenser 130B similar to condenser
130A of loop thermosyphon 100A described in the first embodiment.
More specifically, condenser 130B is unitized as an assembly formed
of header pipe 131 associated with a feed pipe, header pipe 132
associated with a return pipe, the plurality of aligned pipes 133
connecting header pipes 131 and 132 together, and a radiating fin
136 provided in contact with aligned pipes 133.
[0107] Aligned pipe 133 has a linear portion extending in a first
direction (indicated in the figure by an arrow A), and header pipe
132 associated with the return pipe extends in a second direction
(indicated in the figure by an arrow E) traversing the first
direction. Return pipe 140 is connected in a vicinity of one end of
header pipe 132 extending in this one direction.
[0108] Condenser 130B is arranged to incline relative to bottom
surface 301 of casing 300 of a refrigerator or similar equipment.
More specifically, condenser 130B formed of an assembly is arranged
to entirely incline by an angle .theta..sub.2 such that one end
having return pipe 140 connected thereto is positioned to be closer
than the other end corresponding to that opposite to one end.
[0109] More specifically, condenser 130B is arranged to entirely
incline by angle .theta..sub.2 such that condenser 130A has header
pipe 132 inclined in a direction allowing header pipe 132 to have a
smaller distance to bottom surface 301 for one end having return
pipe 140 connected thereto than the other end located opposite to
one end. Note that relative to bottom surface 301 condenser 130B is
not particularly limited in inclination or angle .theta..sub.2,
although it is preferably several degrees to an angle between 10
degrees and 20 degrees. Such inclination can be done for example by
adjusting in geometry an upper and of support 254c of supporting
platform 250 (see FIG. 1).
[0110] Thus by arranging condenser 130B to incline relative to
bottom surface 301 of casing 300 by angle .theta..sub.2 and
connecting return pipe 140 to header pipe 132 at an end closer to
bottom surface 301, allows loop thermosyphon 100B to reliably
operate regardless of how casing 300 is disposed, for the following
reason:
[0111] The working fluid condensed and liquefied in the plurality
of aligned pipes 133 flows through each aligned pipe 133 into
header pipe 132 and thus joins to flow together, and further flows
through return pipe 140 into evaporator 110.
[0112] If header pipe 132 is arranged parallel to bottom surface
301, header pipe 132 is not necessarily arranged horizontally,
depending on how casing 300 is arranged relative to a floor
surface, how the floor surface inclines, and the like. Accordingly,
as shown in FIG. 17, a conventional loop thermosyphon has return
pipe 140 connected to header pipe 132 at a center to provide a
minimum distance to each aligned pipe 133 to allow the working
fluid to smoothly flow.
[0113] If such arrangement is adopted, however, and header pipe 132
is arranged to incline, the working fluid is more, significantly
prevented from flowing in header pipe 132 at a location lower than
the portion connecting header pipe 132 and return pipe 140 together
than at a location higher than that portion. Consequently in the
plurality of aligned pipes 133 the working fluid experiences
different flow resistances and the loop thermosyphon cannot operate
efficiently.
[0114] In the present embodiment loop thermosyphon 100B has header
pipe 132 arranged to previously incline relative to bottom surface
301 of casing 300 of equipment and has return pipe 140 connected to
header pipe 132 at an end closer to bottom surface 301 to allow the
working fluid to smoothly flow. As a result the loop thermosyphon
can be prevented from defective operation attributed to disposition
and thus reliably operate.
Third Embodiment
[0115] The present embodiment provides a loop thermosyphon 100C
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first or second embodiment. Accordingly, the components
similar to those of the first or second embodiment are shown in the
figures with identical reference characters.
[0116] As shown in FIGS. 7A and 7B, the present embodiment provides
loop thermosyphon 100C with a condenser 130C similar to condensers
130A and 130B of loop thermosyphons 100A and 1001B described in the
first and second embodiments. More specifically, condenser 130C is
unitized as an assembly formed of header pipe 131 associated with a
feed pipe, header pipe 132 associated with a return pipe, the
plurality of aligned pipes 133 connecting header pipes 131 and 132
together, and radiating fin 136 provided in contact with aligned
pipes 133.
[0117] In the present embodiment condenser 130C is arranged to
entirely incline by angle .theta..sub.1 to have aligned serpentine
tube 133 with linear portions 134a-134d inclined to be closer to
bottom surface 301 as the serpentine tube approaches header pipe
132. Furthermore condenser 130B is arranged to entirely incline by
angle .theta..sub.2 such that header pipe 132 is inclined in a
direction allowing header pipe 132 to have a smaller distance to
bottom surface 301 for one end having return pipe 140 connected
thereto than the other end located opposite to one end.
[0118] Thus the effect of the first embodiment and that of the
second embodiment can both be achieved. This can significantly
reduce a defective operation of the loop thermosyphon attributed to
disposition. Thus the loop thermosyphon can reliably operate and
the Stirling refrigerating machine can be operated highly
efficiently.
Fourth Embodiment
[0119] The present embodiment provides a loop thermosyphon 100D
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first to third embodiments. Accordingly, the components
similar to those of the first to third embodiments are shown in the
figures with identical reference characters.
[0120] As shown in FIG. 8, loop thermosyphon 100D has a condenser
130D with each aligned pipe 133 defined by linear portions
134a-134e linearly extending in a first direction (in the figure,
direction A), and curved portions 135a-135d connecting linear
portions 134a-134e. Linear portions 134a-134e are arranged, one on
another, vertically in parallel. Curved portions 135a-135d connect
linear portions 134a-134e at their respective ends together. More
specifically, condenser 130D is configured of aligned pipes 133
configured of laterally arranged serpentine tubes. The plurality of
aligned pipes 133 at linear portions 134a-134e have a plurality of
radiating fins 136 assembled thereto.
[0121] Thus if a condenser formed of an assembly having an odd
number of aligned pipes 133 each formed of a serpentine tube is
employed, header pipe 131 associated with the feed pipe and header
pipe 132 associated with the return pipe will separately be
arranged at opposite ends of the condenser. Accordingly, in
contrast to the first or third embodiment, condenser 130D needs to
be arranged to incline to have its rear side to be closer to bottom
surface 301. This allows aligned serpentine tubes 133 to have
linear portions 134a-134e inclined in a direction allowing them to
have a smaller distance to bottom surface 301 as they approach
header pipe 132. Condenser 130D can be arranged to incline relative
to bottom surface 301 of casing 300 for example by adjusting
support 254C of support platform 250 in height (see FIG. 1).
[0122] Thus a condenser having aligned pipes 133 in an odd number
of stages in layers that is entirely inclined relative to a bottom
surface of a casing by angle .theta..sub.1 also allows a loop
thermosyphon to reliably operate regardless of how the casing is
disposed.
Fifth Embodiment
[0123] The present embodiment provides a loop thermosyphon 100E
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first to fourth embodiments. Accordingly, the components
similar to those of the first to fourth embodiments are shown in
the figures with identical reference characters.
[0124] As shown in FIG. 10, loop thermosyphon 100E has a condenser
130E with aligned pipes 133 each defined by linear portions
134a-134c linearly extending in a first direction (in the figure,
direction A) parallel to bottom surface 301 of casing 300 of
equipment, linear portion 134d located at a bottommost stage and
inclined relative to bottom surface 301, and curved portions
135a-135c connecting linear portions 134a-134d. Linear portions
134a-134d have their respective ends connected together by curved
portions 135a-135c. The plurality of aligned pipes 133 at linear
portions 134a-134d have a plurality of radiating fins 136 assembled
thereto.
[0125] Condenser 130E has the bottommost linear portion 134d
inclined in a direction allowing linear portion 134d to have a
smaller distance to bottom surface 301 as linear portion 134d
approaches header pipe 132. In other words, linear portion 134d is
inclined relative to bottom surface 301 by an angle
.theta..sub.3.
[0126] The working fluid flowing in condenser 130E through aligned
pipe 133 is condensed and liquefied mainly at the bottommost linear
portion 134d and pulled by gravity to flow through the inclined
linear portion 134d toward header pipe 132 and flow out of aligned
pipe 133. As such, aligned pipe 133 will not have the liquefied
working fluid staying therein. The bottommost linear portion 134d
previously alone inclined relative to bottom surface 301 of casing
300 by a prescribed angle allows the working fluid to smoothly flow
regardless of how the casing is disposed, and loop thermosyphon
100E can reliably operate.
Sixth Embodiment
[0127] The present embodiment provides a loop thermosyphon 100F
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first to fifth embodiments. Accordingly, the components
similar to those of the first to fifth embodiments are shown in the
figures with identical reference characters.
[0128] As shown in FIG. 11, the present embodiment provides loop
thermosyphon 100F having a condenser 130F with the plurality of
aligned pipes 133 each defined by linearly extending portions
134a-134d and curved portions 135a-135c connecting linear portions
134a-134d together. Linear portions 134a-134d have their respective
ends connected together by curved portions 135a-135c. The plurality
of aligned pipes 133 at linear portions 134a-134d have a plurality
of radiating fins 136 assembled thereto.
[0129] Condenser 130E has linear portions 134a-134d each arranged
to incline in a direction allowing linear portions 134a-134d to
have a smaller distance to bottom surface 301 of casing 300 of the
equipment as the linear portions extend downstream (or extend from
header pipe 131 toward header pipe 132). In particular, the
bottommost linear portion 134d is inclined relative to bottom
surface 301 by an angle .theta..sub.4.
[0130] The working fluid flowing in condenser 130E through aligned
pipe 133 is condensed and liquefied mainly at the bottommost linear
portion 134d. However, as the surrounding temperature or the like
varies, aligned pipe 133 occasionally has the working fluid
condensed and liquefied not only at the bottommost linear portion
134d but also linear portions 134a-134c overlying linear portion
134d. Linear portions 134a-134d each arranged to incline by a
prescribed angle to allow the working fluid condensed and thus
liquefied in linear portions 134a-134d to be pulled by gravity to
return through the inclined linear portions 134a-134c toward header
pipe 132, can prevent aligned pipe 133 from having the working
fluid staying therein.
[0131] Linear portions 134a-134d thud previously arranged to
incline relative to bottom surface 301 of casing 300 by a
prescribed angle allows the working fluid to smoothly flow
regardless of how casing 300 is disposed, and as a result allow
loop thermosyphon 100F to reliably operate.
Seventh Embodiment
[0132] The present embodiment provides a loop thermosyphon 100G
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first to sixth embodiments. Accordingly, the components
similar to those of the first to sixth embodiments are shown in the
figures with identical reference characters.
[0133] As shown in FIG. 12, the present embodiment provides loop
thermosyphon 100G including a condenser 130G having header pipe 131
associated with a feed pipe and extending vertically, header pipe
132 associated with a return pipe and also extending vertically,
and the plurality of aligned pipes 133 connecting header pipes 131
and 132 together. The plurality of aligned pipes 133 are each a
linearly extending pipe and a plurality of such linear tubes are
vertically arranged in parallel layers to form condenser 130G. The
plurality of aligned pipes 133 has a plurality of radiating fins
136 assembled thereto. Note that in condenser 130G header pipe 131
extends in a direction orthogonal that in which each aligned pipe
133 extends and header pipe 132 extends in a direction orthogonal
to that in which each aligned pipe 133 extends.
[0134] In the present embodiment loop thermosyphon 100G has
condenser 130G arranged to entirely incline relative to bottom
surface 301 of casing 300 of equipment by an angle .theta..sub.5 so
that condenser 130G has aligned pipes 133 each arranged to incline
in a direction allowing the aligned pipe to have a smaller distance
to bottom surface 301 of casing 300 of the equipment as the aligned
pipe extends downstream (or extends from header pipe 131 toward
header pipe 132).
[0135] Condenser 130G previously, entirely inclined to allow the
working fluid condensed and thus liquefied in aligned pipe 133 to
be pulled by gravity to return through aligned pipe 133 toward
header pipe 132, can prevent aligned pipe 133 from having the
working fluid staying therein. The working fluid can smoothly flow
regardless of how casing 300 is disposed, and as a result loop
thermosyphon 100F can reliably be operated.
[0136] While the present embodiment has been described by
exemplifying a condenser with header pipes associated with feed and
return pipes, respectively, arranged to vertically extend, the
header pipes may be arranged to extend horizontally. If the header
pipes are thus arranged, the header pipes will be connected by
parallel or linear tubes arranged horizontally in parallel. In that
case, the condenser is similarly arranged to entirely incline
relative to a bottom surface of a casing of equipment by a
prescribed angle so that the condenser has the aligned pipes each
arranged to incline in a direction allowing the aligned pipe to
have a smaller distance to the bottom surface as the aligned pipe
extends downstream (or extends from the header pipe associated with
the feed pipe toward that associated with the return pipe). The
loop thermosyphon can reliably operate.
[0137] Furthermore, the header pipes associated with the feed and
return pipes, respectively, may not be connected by aligned pipes
arranged in a single row. For example the aligned pipes may be
staggered in a direction traversing that in which the aligned pipes
extend.
Eighth Embodiment
[0138] The present embodiment provides a loop thermosyphon 100H
also utilized as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine, similarly as described
in the first to seventh embodiments. Accordingly, the components
similar to those of the first to seventh embodiments are shown in
the figures with identical reference characters.
[0139] As shown in FIG. 13, the present embodiment provides loop
thermosyphon 100H including a condenser 130H having header pipe 131
associated with a feed pipe and extending vertically, header pipe
132 associated with a return pipe and also extending vertically,
and the plurality of aligned pipes 133 connecting header pipes 131
and 132 together. The plurality of aligned pipes 133 are each a
linearly extending pipe and a plurality of such linear tubes are
vertically arranged in parallel layers to form condenser 130H. The
plurality of aligned pipes 133 has a plurality of radiating fins
136 assembled thereto. Note that for loop thermosyphon 100H header
pipes 131 and 132 are arranged such that header pipes 131 and 132
extend in a direction overlapping a normal to bottom surface 301 of
casing 300 of equipment.
[0140] In the present embodiment loop thermosyphon 100H has linear
aligned pipes 133 arranged to entirely incline relative to bottom
surface 301 by an angle .theta..sub.6 so that condenser 130G has
aligned pipes 133 each arranged to incline in a direction allowing
the aligned pipe to have a smaller distance to bottom surface 301
as the aligned pipe extends downstream (or extends from header pipe
131 toward header pipe 132).
[0141] Aligned pipe 133 previously inclined to allow the working
fluid condensed and thus liquefied therein to be pulled by gravity
to return therethrough toward header pipe. 132, can be prevented
from having the working fluid staying therein. The working fluid
can smoothly flow regardless of how casing 300 is disposed, and as
a result loop thermosyphon 100G can reliably be operated.
[0142] While the present embodiment has been described by
exemplifying a condenser with header pipes associated with feed and
return pipes, respectively, arranged to vertically extend, the
header pipes may be arranged to extend horizontally. If the header
pipes are thus arranged, the header pipes will be connected by
parallel, linear tubes arranged horizontally in parallel. In that
case, the condenser is similarly arranged to entirely incline
relative to a bottom surface of a casing of equipment by a
prescribed angle so that the condenser has the aligned pipes each
arranged to incline in a direction allowing the aligned pipe to
have a smaller distance to the bottom surface as the aligned pipe
extends downstream (or extends from the header pipe associated with
the feed pipe toward that associated with the return pipe). The
loop thermosyphon can reliably operate.
[0143] Furthermore, the header pipes associated with the feed and
return pipes, respectively, may not be connected by aligned pipes
arranged in a single row. For example the aligned pipes may be
staggered in a direction traversing that in which the aligned pipes
extend.
Ninth Embodiment
[0144] The present embodiment provides a Stirling refrigerator
having the loop thermosyphon of any of the first to eighth
embodiments as a heat transfer system associated with a heated
portion of a Stirling refrigerating machine disposed in a
casing.
[0145] As shown in FIG. 14, the present embodiment provides a
Stirling refrigerator 1000 including a freezer section 1028 and a
chiller section 1029 as a refrigeration section. Stirling
refrigerator 1000 includes loop thermosyphon 100 as a heat transfer
system associated with a heated portion to cool a heated portion
204 of a Stirling refrigerating machine 200. Stirling refrigerating
machine 200 has a cold portion 206 generating cryogenic temperature
utilized by a heat transfer system 1020 associated with the cold
portion (indicated in FIG. 14 by a broken line) to cool the
refrigerator's interior. As well as the heat transfer system
associated with the heated portion, the heat transfer system
associated with the cold portion may also be configured of a loop
thermosyphon or may be a heat transfer system utilizing forced
convection.
[0146] The heat transfer system associated with the heated portion,
or loop thermosyphon 100, includes evaporator 110 attached to
surround and thus contact heated portion 204 of Stirling
refrigerating machine 200, and condenser 130 connected to
evaporator 110 by a feed pipe and a return pipe. Evaporator 110,
condenser 130 and feed and return pipes 120 and 140 form a
circulation circuit having ethanol-added water or the like sealed
therein as a coolant. To allow the coolant's evaporation and
condensation and resultant natural circulation to be utilized to
transfer heat generated at heated portion 204, condenser 130 is
arranged to be upper (or higher) than evaporator 110.
[0147] As shown in FIG. 14, Stirling refrigerating machine 200 is
arranged in Stirling refrigerator 1000 at a rear, upper portion.
Furthermore, heat transfer system 1020 associated with the cold
portion is arranged in Stirling refrigerator 1000 closer to the
rear side. In contrast, the heat transfer system associated with
the heated portion, or loop thermosyphon 100, is arranged in
Stirling refrigerator 1000 at an upper portion. Note that
thermosyphon 100 has condenser 130 provided in a duct 1024 provided
in Stirling refrigerator 1000 at an upper portion.
[0148] When Stirling refrigerating machine 200 is operated, heated
portion 204 generates heat, which is thermally exchanged via
condenser 130 of thermosyphon 100 with air present in duct 1024. An
air blowing fan 1025 exhausts warm air present in duct 1024 to
outside Stirling refrigerator 100 and also introduces air external
to Stirling refrigerator 1000 to help to exchange heat.
[0149] In contrast, cold portion 206 generates cryogenic
temperature, which is thermally exchanged with an air stream
present in cold duct 1023, as indicated in FIG. 14 by an arrow. A
fan 1026 associated with a freezer section and a fan 1027
associated with a chiller section blow cooled, cold air toward
freezer section 1028 and chiller section 1029, respectively. Each
refrigeration section 1028, 1029 provides a warm air stream which
is again introduced into cold duct 1023 and repeatedly cooled.
[0150] As loop thermosyphon 100 mounted in Stirling refrigerator
1000 as described above is any of loop thermosyphons 100A-100H
described in the first to eighth embodiments, it can reliably
operate regardless of how Stirling refrigerator 100 has a casing
disposed. Stirling refrigerating machine 200 can be operated
significantly efficiently and Stirling refrigerator 1000 can also
be improved in performance.
Tenth Embodiment
[0151] The present embodiment provides a cooling apparatus having a
major portion common in structure to that of the second
conventional example described hereinbefore. Accordingly,
components identical to those of the cooling apparatus of the
second conventional example are identically labeled.
[0152] As shown in FIGS. 15, and 16A and 16B, the present
embodiment provides a cooling apparatus having condensate coolant
pipe 11 having vertical pipes 11A and 11B with their respective
upper ends connected to a lateral pipe 11C at one and the other
ends, respectively, and their respective lower ends connected to
semi-rings 6A and 6B at their respective outer circumferential
upper ends, respectively, similarly as has been done in the second
conventional example. Thus vertical pipes 11A and 11B are connected
at upper and lower ports that do not match as seen horizontally.
Accordingly, vertical pipes 11A and 11B are implemented by bent
pipes having inclined portions 11Aa and 11Ba having a downward
gradient (see FIG. 16A). If cooling apparatus 50 (see FIG. 20) more
or less inclines, lateral pipe 11C will have one of the ends lowest
in level of the entirety of lateral pipe 11C. The coolant's
condensate will flow through the vertical pipe having a lower inlet
and thus be prevented from staying in lateral pipe 11C.
[0153] In general, refrigerators are to be installed at places
having an inclination of at most 5.degree. including no
inclination. Accordingly by setting at least 5.degree. for a
downward gradient .alpha. of inclined portions 11Aa and 11Ba of the
vertical pipes with reference to cooling apparatus 500 placed with
no inclination (see FIG. 16A), the vertical pipes can have inclined
portions 11Aa and 11Ba with the downward gradient maintained if
cooling apparatus 50 is inclined by 5.degree., and the thermosyphon
can be prevented from failing to function. Thus the coolant can
reliably be circulated.
[0154] Furthermore, vapor coolant pipe 11 has lateral pipe 11C with
a degassing charge pipe 21 attached thereto. If the heat transfer
cycle associated with the heated portion is operated with water
used as a coolant, an uncondensed gas (or air) solved and thus
present in water needs to be removed. Accordingly, after the water
or coolant is shielded charge pipe 21 is used to vacuum a shielded
system internal to the cycle. Charge pipe 21 attached at a location
high in level can prevent water from being sucked in vacuuming the
shielded system and can also improve efficiency in vacuuming the
system.
[0155] The first to tenth embodiments have been described by
exemplifying a loop thermosyphon employed in a heat transfer system
associated with a heated portion of a Stirling refrigerating
machine, the present invention is as a matter of course also
applicable to other devices having a heat source.
[0156] Furthermore, characteristic configurations described in the
first to tenth embodiments can be combined together.
[0157] The above disclosed embodiments are by way of illustration
and example only and are not to be taken by way of limitation, the
spirit and scope of the present invention being limited only by the
terms of the appended claims and encompassing any variation falling
within a meaning and scope equivalent to the claims.
* * * * *