U.S. patent application number 12/080439 was filed with the patent office on 2008-10-09 for heat storage tank.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Yoshio Miyata, Takashi Toyoshima.
Application Number | 20080245319 12/080439 |
Document ID | / |
Family ID | 39809804 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080245319 |
Kind Code |
A1 |
Toyoshima; Takashi ; et
al. |
October 9, 2008 |
Heat storage tank
Abstract
A heat storage tank 10 comprises a plastic container 11 for
storing engine cooling water, an inflow pipe 30 and an outflow pipe
31 communicating with the interior of plastic container 11 and
formed to project from plastic container 11, and a heat-insulating
layer 13 arranged to cover the whole periphery of plastic container
11 to insulate the heat of the engine cooling water in plastic
container 11. Heat-insulating layer 13 is arranged to cover the
roots of pipes 30, 31. Therefore, the heat radiation of the engine
cooling water from the bases of pipes 30, 31 can be suppressed
thereby preventing a reduction in heat insulation effect.
Inventors: |
Toyoshima; Takashi;
(Obu-city, JP) ; Miyata; Yoshio; (Nagoya-city,
JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
39809804 |
Appl. No.: |
12/080439 |
Filed: |
April 2, 2008 |
Current U.S.
Class: |
123/41.14 |
Current CPC
Class: |
F01P 2060/08 20130101;
F28D 20/0034 20130101; Y02E 60/14 20130101; F01P 2011/205 20130101;
F01P 2003/027 20130101; Y02E 60/142 20130101 |
Class at
Publication: |
123/41.14 |
International
Class: |
F01P 11/02 20060101
F01P011/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 3, 2007 |
JP |
2007-097392 |
Claims
1. A heat storage tank comprising: a tank body for storing a fluid;
pipes communicating with the interior of the tank body and formed
to project from the tank body; and a heat-insulating layer arranged
to cover the whole periphery of the tank body including the roots
of the pipes and thus to insulate the heat of the fluid in the tank
body.
2. The heat storage tank according to claim 1, wherein the tank
body is formed of a synthetic resin material, wherein an inner air
blocking layer is formed on the outer surface of the tank body for
preventing the air passage, wherein the heat-insulating layer is
arranged on the outside of the inner air blocking layer, wherein an
outer air blocking layer is arranged so as to cover the
heat-insulating layer for preventing the air passage, and wherein
the inner and outer air blocking layers are coupled to each other
by the edges thereof, and the space between the inner and outer air
blocking layers is hermetically closed.
3. The heat storage tank according to claim 2, wherein joints for
coupling the inner air blocking layer and the outer air blocking
layer to each other are arranged on the outer periphery of the
pipes.
4. The heat storage tank according to claim 3, wherein the joints
between the inner air blocking layer and the outer air blocking
layer are arranged only on the outer periphery of the pipes.
5. The heat storage tank according to claim 1, wherein the pipes
include a first pipe communicating with the interior of the tank
body and formed in such a manner as to be projected from the tank
body for supplying a fluid into the tank body, and a second pipe
communicating with the interior of the tank body and formed in such
a manner as to be projected from the tank body for discharging the
fluid out of the tank body, and wherein the tank body comprises a
plurality of partition plates arranged therein so that the influent
fluid from the first pipe flows out from the second pipe after
flowing in zigzag in the tank body.
6. The heat storage tank according to claim 5, wherein the pipes
are arranged at the lower part of the tank body.
7. The heat storage tank according to claim 1, wherein the
heat-insulating layer has the heat conductivity of not more than
0.01 (kcal/hm .degree. C.).
8. The heat storage tank according to claim 1, wherein the fluid is
the engine cooling water of the automotive vehicle.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a heat storage tank for storing
and insulating a liquid.
[0003] 2. Description of the Related Art
[0004] A cooling system for promoting the warm-up of a water-cooled
internal combustion engine of an automotive vehicle has
conventionally been proposed in which a heat storage tank for
storing and insulating the engine cooling water flowing out of the
water-cooled engine is arranged in the cooling water circuit and
the high-temperature cooling water stored in the heat storage tank
is introduced to the engine to accelerate engine warm-up. This
makes it possible to utilize the extraneous heat of the engine
effectively and reduce the fuel consumption from the overall
viewpoint of the vehicle operation.
[0005] Generally, the heat storage tank has a double
heat-insulating structure including an inner cylindrical tank of
stainless steel making up a heat storage tank body and an outer
cylindrical tank of stainless steel, wherein the space between the
inner and outer cylindrical tanks is kept substantially in
vacuum.
SUMMARY OF THE INVENTION
[0006] However, the heat storage tank described above requires two
tanks including inner and outer cylindrical tanks which results in
increased cost.
[0007] In view of the above, the object of this invention is to
provide a heat storage tank for reducing cost while at the same
time maintaining the insulation effect.
[0008] In order to achieve the above object, according to this
invention, there is provided a heat storage tank comprising a tank
body (11) for storing a fluid, pipes (30, 31) communicating with
the interior of the tank body and formed to project from the tank
body, and a heat-insulating layer (13) arranged to cover the whole
periphery of the tank body including the roots of the pipes and
thus to insulate the heat of the fluid in the tank body.
[0009] As a result, the use of only a single tank body can reduce
the cost without using two tanks, i.e. inner and outer cylindrical
tanks.
[0010] In addition, since the heat-insulating layer is arranged in
such a manner as to cover the whole periphery of the tank body
including the bases of the first and second pipes, heat radiation
from the bases of the first and second pipes can be suppressed,
thereby making it possible to maintain the heat insulation
effect.
[0011] Incidentally, the reference numerals inserted in the
parentheses following the names of the respective means described
above represent the correspondence with the specific means,
respectively, included in the embodiments described below.
[0012] The present invention may be more fully understood from the
description of preferred embodiments of the invention, as set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram showing a configuration of a cooling
water circuit used for a heat storage tank for automotive vehicles
according to this invention.
[0014] FIG. 2 shows the external appearance of the vehicle heat
storage tank shown in FIG. 2.
[0015] FIG. 3 is a sectional view showing the vehicle heat storage
tank shown in FIG. 2.
[0016] FIG. 4 is a perspective view showing the interior of the
vehicle heat storage tank shown in FIG. 2.
[0017] FIG. 5 is a diagram showing the flow of the engine cooling
water in the vehicle heat storage tank shown in FIG. 2.
[0018] FIG. 6 is a diagram showing the assembly steps for the
vehicle heat storage tank shown in FIG. 2.
[0019] FIG. 7 is a diagram explaining the forming of the film layer
shown in FIG. 6.
[0020] FIG. 8 is a diagram explaining the forming of the film layer
shown in FIG. 6.
[0021] FIG. 9 is a diagram explaining the forming of the film layer
shown in FIG. 6.
[0022] FIG. 10 is a diagram explaining the forming of the film
layer shown in FIG. 6.
[0023] FIG. 11 is a diagram explaining the forming of the film
layer shown in FIG. 6.
[0024] FIG. 12 is a diagram explaining the forming of the film
layer shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] FIG. 1 shows a configuration of the cooling water circuit
using the vehicle heat storage tank according to an embodiment of
the invention.
[0026] The cooling water circuit includes a heat storage tank 10, a
four-way valve 20, a heater core 30 and an electrically-operated
pump 40. Heat storage tank 10 is for insulating and storing the
engine cooling water. Four-way valve 20 connects the outlet side of
one of a cylinder head 50 and a cylinder block 51 of the engine to
the inlet side of at least one of heater core 30 and heat storage
tank 10.
[0027] Heater core 30, which makes up a vehicle air conditioning
system, is a heat exchanger for heating the air with the engine
cooling water. Electrically-operated pump 40 is a circulation pump
for supplying the engine cooling water toward the inlet side of
each of cylinder head 50 and cylinder block 51.
[0028] In the cooling water circuit, a connection is established
only between the outlet side of cylinder block 51 and the inlet
side of heat storage tank 10 by four-way valve 20 while the
temperature of the cooling water is low. As a result, the cooling
water stored in heat storage tank 10 can be supplied into cylinder
block 51 thereby accelerating the warm-up of cylinder block 51.
[0029] In the process, the inlet side of heater core 30 is shut off
by four-way valve 20, and therefore the cooling water from heat
storage tank 10 flows only to cylinder block 51. Thus, the warm-up
of cylinder block 51 can efficiently promoted.
[0030] Upon a subsequent temperature increase of the cooling water
to a middle level, four-way valve 20 closes the communication
between the outlet side of cylinder block 51 and the inlet side of
heat storage tank 10, while at the same time connecting the outlet
side of cylinder head 50 and the inlet side of heater core 30.
[0031] In the process, the engine cooling water (hot water) can be
kept in cylinder block 51, and therefore the engine warm-up is
accelerated. Further, the engine cooling water heated by cylinder
head 50 is circulated between cylinder head 50 and heater core 30,
and therefore the air can be heated by heater core 30.
[0032] Upon subsequent increase of water temperature to a high
level, four-way valve 20 connects the outlet side of cylinder head
50 to the inlet side of heater core 30 and the inlet side of heat
storage tank 10. Then, the engine cooling water flows into heat
storage tank 10, and therefore the engine cooling water (hot water)
for the next warm-up can be stored in heat storage tank 10.
[0033] The structure of heat storage tank 10 will be explained.
FIG. 2 shows the appearance of heat storage tank 10, and FIG. 3 is
a sectional view taken in the plane A in FIG. 2.
[0034] Heat storage tank 10, as shown in FIG. 2, is cubic and has
an inflow pipe 30 and an outflow pipe 31 projected outward from the
lower part of the side wall thereof. Specifically, heat storage
tank 10, as shown in FIG. 3, includes a plastic container (tank
body) 11 and a heat-insulating member 15 surrounding the whole
outer periphery of container 11. Heat-insulating member 15 contains
both the exterior of tank body 11 formed as a polyhedron and the
base portions of inflow pipe 30 and outflow pipe 31 at the same
time. Heat-insulating member 15 includes a plating layer 12
constituting an inner air blocking layer, heat-insulating layer 13
and a film layer 14 constituting an outer air blocking layer.
[0035] Plastic container 11 has a cubic structure by combining
first and second division casings. Plastic container 11 is
connected to inflow pipe 30 and outflow pipe 31 communicating with
the interior thereof. Inflow pipe 30 and outflow pipe 31 are formed
of a synthetic resin.
[0036] Plastic container 11 and pipes 30, 31 are formed of a
synthetic resin material, such as PPS, PPA or NY66, mixed with
glass fiber. Plastic container 11 and pipes 30, 31 are formed of a
member having the thickness of 1 mm to 5 mm.
[0037] Plating layer 12 is a thin metal coating (of aluminum, for
example) formed by the plating process in such a manner so as to
cover the outer surface of plastic container 11. Heat-insulating
layer 13 is formed to cover the whole outer surface of plastic
container 11 including the bases of inflow pipe 30 and outflow pipe
31. Heat-insulating layer 13 is formed of glass wool, rock wool,
urethane foam or polystyrene and the like. Heat-insulating layer 13
has the heat conductivity of not more than 0.01 (kcal/hm .degree.
C.). Film layer 14 is formed of a laminate film and surrounds the
whole of heat-insulating layer 13. Film layer 14 and plating layer
12 are formed to prevent the transmission of air.
[0038] Plating layer 12 covers the entire outer surface of tank
body 11 and the bases of inflow pipe 30 and outflow pipe 31. As a
result, the edges of the plating layer 12 is exposed only as two
annular edges around the outer periphery of inflow pipe 30 and the
outer periphery of outflow pipe 31. On the other hand, film layer
14 is formed in the shape of a cylinder or a bag by folding a
tabular film blank and bonding the edges thereof to each other.
Film layer 14 has two annular edges around the periphery of inflow
pipe 30 and the periphery of outflow pipe 31. Plating layer 12 and
film layer 14 are bonded at two points around inflow pipe 30 and
the periphery of outflow pipe 31. This configuration is effective
for suppressing the heat transfer from plating layer 12 to film
layer 14. Joints 21, 23 between plating layer 12 and film layer 14
are referred to as first joints, while joints 20, 22 between film
layers 14 are referred to as second joints.
[0039] FIGS. 4 and 5 show the internal structure of heat storage
tank 10. A plurality of partition plates 40 are arranged in
parallel to each other in the vertical direction in heat storage
tank 10. Each space between the plurality of partition plates 40
forms a parallel flow path 41. Parallel flow paths 41 are to supply
the engine cooling water in vertical direction.
[0040] The plurality of partition plates 40 are vertically offset
alternately in staggered fashion, and are supported by the bottom
surface or the ceiling of heat storage tank 10.
[0041] Turn paths 42, 43 for turning the flow of the engine cooling
water are formed on the upper or lower side of the plurality of
partition plates 40. Turn paths 42, 43 are arranged alternately in
the direction in which partition plates 40 are arranged. Turn paths
42 turn the upward flow downward. Turn paths 43 turn the downward
flow upward.
[0042] The plurality of partition plates 40 are formed of a
synthetic resin material integrally with plastic container 11 and
pipes 30, 31. The plurality of partition plates 40 are formed of
the thickness of 1 mm to 2 mm.
[0043] In this configuration, the engine cooling water flows in the
plurality of parallel paths 41 and the plurality of turn paths 42
and 43. The engine cooling water thus flows in zigzag as indicated
by arrows in FIG. 5. As a result, the engine cooling water flowing
in from inflow pipe 30 can flow out from outflow pipe 31 without
mixing with the engine cooling water previously existing inside
heat storage tank 10.
[0044] A method of manufacturing heat storage tank 10 according to
this embodiment will be explained.
[0045] FIG. 6 is a diagram showing the assembly steps, and FIGS. 7
and 8 are diagrams showing the steps of forming film layer 14.
[0046] First, plastic container 11 is formed, as shown in (a) of
FIG. 6, by combining first and second division casings 11a,
11b.
[0047] Next, a thin metal coating is formed, as shown in (b) of
FIG. 6, by plating the whole outer surface of plastic container 11.
In the process, the thin metal coating is formed in such a manner
as to cover the respective roots of pipes 30, 31. Thus, plating
layer 12 is formed.
[0048] Then, heat-insulating layer 13 is formed on the outside of
plating layer 12. Specifically, glass wool (i.e. heat-insulating
material) is arranged in such a manner as to cover the whole outer
surface of plastic container 11 including the roots of pipes 30, 31
as shown in (c) of FIG. 6.
[0049] Next, film layer 14 is formed, as shown in (d) of FIG. 6, on
the outside of heat-insulating layer 13.
[0050] Specifically, as shown in FIG. 7, a rectangular laminate
film 14a is prepared, and folded back in channel shape as shown in
FIG. 8.
[0051] Then, as shown in FIG. 9, two end portions 14b, 14c of
laminate film 14a are heat sealed to each other. As a result,
laminate film 14a is formed in the shape of a rectangular tube.
[0052] Then, as shown in FIG. 10, circular holes 140, 141 are
formed in the upper parts of the two opposed side walls of laminate
film 14a in the shape of a rectangular tube.
[0053] Then, circular holes 140, 141 are extruded by the heat press
process, thereby forming cylindrical portions 140a, 141a as shown
in FIG. 11.
[0054] Next, upper end portions 142, 143 of laminate film 14a in
the shape of a rectangular tube are folded into overlapped form and
heat sealed to other. As a result, a heat seal portion 22 (FIG. 3)
is formed at the upper end of laminate film 14a. Heat seal portion
22 represents a part where upper end portions 142, 143 are closely
attached to each other by heat sealing.
[0055] Laminate film 14a is formed into the shape of a rectangular
tube, and upper end portions 142, 143 thereof are hermetically
closed. After that, plastic container 11 with plating layer 12 and
heat-insulating layer 13 is inserted into laminate film 14a in the
shape of a rectangular tube as described above.
[0056] Then, pipes 30, 31 are inserted into cylindrical portions
140a, 141a, respectively. As a result, a first gap is created
between cylindrical portion 140a and pipe 30, and a second gap
between cylindrical portion 141a and pipe 31.
[0057] Lower end portions 144, 145 of laminate film 14a in the
shape of a rectangular tube are folded into overlapped form and
heat sealed to other ((d) in FIG. 6). As a result, heat seal
portion 20 (FIG. 3) is formed at the lower part of laminate film
14a. Heat seal portion 20 represents a part where lower end
portions 144, 145 are heat sealed to other.
[0058] Then, vacuum is introduced from the first and second gaps
described above. In addition, cylindrical portion 140a of laminate
film 14a of pipe 30 is heat sealed to plating layer 12. In pipe 31,
cylindrical portion 141a of laminate film 14a is heat sealed to
plating layer 12.
[0059] As a result, heat seal portions 21, 23 (FIG. 3) are formed
on laminate film 14a. Heat seal portion 21 represents a part where
cylindrical portion 140a (FIG. 12) of laminate film 14a is heat
sealed to plating layer 12 on the outer surface of pipe 30. Heat
seal portion 23 represents a part where cylindrical portion 141a
(FIG. 12) of laminate film 14a is heat sealed to plating layer 12
on the outer surface of pipe 31. Thus, the space between plating
layer 12 and laminate layer 14a is substantially formed in a
vacuum.
[0060] According to the embodiments described above, heat storage
tank 10 includes plastic container 11 for storing the engine
cooling water, inflow pipe (first pipe) 30 and outflow pipe (second
pipe) 31 communicating with the interior of plastic container 11
and formed in such a manner as to be projected from plastic
container 11, and heat-insulating layer 13 arranged to cover the
whole periphery of plastic container 11 and to insulate the engine
cooling water in plastic container 11, wherein heat-insulating
layer 13 is arranged to cover also the roots of pipes 30, 31.
[0061] Thus, the heat of the engine cooling water is prevented from
being radiated from the bases of pipes 30, 31. Only one plastic
container (tank body) 11 is used, but not two tanks including inner
and outer cylindrical tanks, thereby reducing the cost. Therefore,
the cost can be reduced while at the same time maintaining the
insulation effect.
Other Embodiments
[0062] The embodiments described above represent a case in which a
thin metal coating is formed as plating layer 12 on the outer
surface of plastic container 11. As an alternative for plating
layer 12, a thin film made of a synthetic resin material which can
shut off the air may be used. The film material may be formed to
cover the exterior of plastic container 11 in place of plating
layer 12. In this case, the inner film layer replacing plating
layer 12 covers the whole tank body 11, and is formed in such a
manner as to locate an edge adapted to be bonded with the outer
film layer only around pipes 30, 31.
[0063] The embodiments described above represent a case in which
the space between plating layer 12 and film layer 14 is formed in a
vacuum to improve the heat insulation characteristic. Nevertheless,
the space may not be formed in a vacuum.
[0064] The embodiments described above represent a case in which
plastic container 11 is used as a tank body. As an alternative, a
metal tank may be used as a tank body.
[0065] The embodiments described above represent a case in which
inflow pipe 30 and outflow pipe 31 are formed in such a manner as
to be projected outward at the lower part of the side wall of
plastic container 11. However, the invention is not limited to this
configuration, but inflow pipe 30 and outflow pipe 31 may be
arranged at any point on plastic container 11. Also, in place of
the configuration in which two pipes 30, 31 are extended
independently of each other in spaced relation with each other, a
configuration may be employed in which pipes 30, 31 are adjacent to
each other or provided as a single double pipe.
[0066] The embodiments described above represent a case in which
the engine cooling water is used as the fluid. As an alternative,
other fluids such as the oil may be used.
[0067] The embodiments described above represent a case in which
heat storage tank 10 is mounted on the vehicle. As an alternative,
heat storage tank 10 may be used with any of various devices such
as a container for insulating the hot bath water.
[0068] While the invention has been described with reference to
specific embodiments chosen for purposes of illustration, it should
be apparent that numerous modifications could be made thereto by
those skilled in the art without departing from the basic concept
and scope of the invention.
* * * * *