U.S. patent application number 14/407844 was filed with the patent office on 2015-06-18 for cold storage heat exchanger.
The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Takashi Danjyo, Seiji Inoue, Shin Nishida, Atsushi Yamada.
Application Number | 20150168047 14/407844 |
Document ID | / |
Family ID | 49757835 |
Filed Date | 2015-06-18 |
United States Patent
Application |
20150168047 |
Kind Code |
A1 |
Danjyo; Takashi ; et
al. |
June 18, 2015 |
COLD STORAGE HEAT EXCHANGER
Abstract
A cold storage heat exchanger for exchanging heat with air
flowing therearound includes a refrigerant passage in which
refrigerant flows, and a cold storage container that accommodates
therein cold storage materials which exchanges heat with the
refrigerant flowing through the refrigerant passage and retains the
amount of heat from the refrigerant. The cold storage materials
having different melting points are accommodated in the cold
storage container.
Inventors: |
Danjyo; Takashi;
(Kariya-city, JP) ; Yamada; Atsushi; (Anjo-city,
JP) ; Inoue; Seiji; (Nukata-gun, JP) ;
Nishida; Shin; (Anjo-city, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city, Aichi-pref. |
|
JP |
|
|
Family ID: |
49757835 |
Appl. No.: |
14/407844 |
Filed: |
May 13, 2013 |
PCT Filed: |
May 13, 2013 |
PCT NO: |
PCT/JP2013/003040 |
371 Date: |
December 12, 2014 |
Current U.S.
Class: |
62/467 |
Current CPC
Class: |
F25B 39/022 20130101;
F28D 1/05383 20130101; F28D 20/026 20130101; F25B 2400/24 20130101;
Y02E 60/145 20130101; Y02E 60/14 20130101; F28D 2021/0071 20130101;
F28D 2020/0013 20130101; F25D 17/00 20130101 |
International
Class: |
F25D 17/00 20060101
F25D017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 14, 2012 |
JP |
2012-135042 |
Claims
1. A cold storage heat exchanger for exchanging heat with air
flowing therearound, the cold storage heat exchanger comprising: a
refrigerant passages in which refrigerant flows; and a cold storage
container that accommodates therein a plurality of cold storage
materials which exchange heat with the refrigerant flowing through
the refrigerant passage and which retain an amount of heat from the
refrigerant, wherein the plurality of cold storage materials having
different melting points are accommodated in the cold storage
container.
2. The cold storage heat exchanger according to claim 1, wherein:
the plurality of cold storage materials include a cold storage
material having a high melting point, and a cold storage material
having a low melting point; and the cold storage material having
the high melting point is provided on an upstream side of the cold
storage material having the low melting point in a flow direction
of air.
3. The cold storage heat exchanger according to claim 1, wherein:
the cold storage container is one of a plurality of cold storage
containers; one type of cold storage material of the plurality of
cold storage materials is accommodated in each of the plurality of
cold storage containers; and a cold storage material of the
plurality of cold storage materials that is accommodated in at
least a part of the plurality of cold storage containers has a
different melting point from that of a cold storage material of the
plurality of cold storage materials that is accommodated in another
one of the plurality of cold storage containers.
4. The cold storage heat exchanger according to claim 1, wherein:
the plurality of cold storage materials are two cold storage
materials having different melting points; a melting point of a
cold storage material of the two cold storage materials that has a
high melting point ranges from 5.degree. C. to 25.degree. C.; a
melting point of a cold storage material of the two cold storage
materials that has a low melting point ranges from 0.degree. C. to
15.degree. C.; and when the melting point of the cold storage
material having the high melting point ranges from 5.degree. C. to
15.degree. C., the melting point of the cold storage material
having the low melting point is 0.degree. C. or higher, and is
lower than the melting point of the cold storage material having
the high melting point.
5. The cold storage heat exchanger according to claim 1, further
comprising a refrigerant pipe that is disposed on a least one
surface of the cold storage container, wherein the refrigerant pipe
includes the refrigerant passages.
6. The cold storage heat exchanger according to claim 2, wherein:
the cold storage container includes a plurality of cases
independent of each other; the plurality of cases are arranged to
be different between on an upstream side and on a downstream side
in the flow direction of air; and each of the plurality of cold
storage materials having different melting points is accommodated
in a corresponding one of the plurality of cases.
7. The cold storage heat exchanger according to claim 6, wherein
each of the plurality of cases includes at least one sealing port
through which its corresponding one of the plurality of cold
storage materials is sealed.
8. The cold storage heat exchanger according to claim 1, further
comprising a partition that divides inside of the cold storage
container, wherein each of the plurality of cold storage materials
having different melting points is accommodated in a corresponding
one of a plurality of spaces divided by the partition.
9. The cold storage heat exchanger according to claim 8, wherein
the cold storage container includes at least one sealing port
through which the plurality of cold storage materials are
sealed.
10. The cold storage heat exchanger according to claim 7, wherein
the at least one sealing port is provided at an outer periphery of
the cold storage container or its corresponding one of the
plurality of cases on an upstream side or on a downstream side in
the flow direction of air.
11. The cold storage heat exchanger according to claim 1, wherein
the plurality of cold storage materials include paraffin or hydrate
as their main component.
12. The cold storage heat exchanger according to claim 4, wherein:
a carbon number of paraffin used for the cold storage material
having the high melting point is 16 or 15; a carbon number of
paraffin used for the cold storage material having the low melting
point is 15 or 14; when the carbon number of paraffin for the cold
storage material having the high melting point is 16, the carbon
number of paraffin for the cold storage material having the low
melting point is 15 or 14; and when the carbon number of paraffin
for the cold storage material having the high melting point is 15,
the carbon number of paraffin for the cold storage material having
the low melting point is 14.
13. The cold storage heat exchanger according to claim 9, wherein
the at least one sealing port is provided at an outer periphery of
the cold storage container or its corresponding one of the
plurality of cases on an upstream side or on a downstream side in
the flow direction of air.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on Japanese Patent Application No.
2012-135042 filed on Jun. 14, 2012, the disclosure of which is
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a cold storage heat
exchanger used for a refrigeration cycle device.
BACKGROUND ART
[0003] Conventionally, a refrigeration cycle device is used for an
air-conditioning system. An attempt is made to provide limited
refrigerated air-conditioning even in a state where this
refrigeration cycle device is stopped. For example, in an
air-conditioning system for a vehicle, the refrigeration cycle
device is driven by an engine for traveling. For this reason, when
the engine stops while the vehicle is making a brief stop, the
refrigeration cycle device is stopped. An "idle reduction vehicle"
which stops its engine while the vehicle is stopped, waiting for a
traffic light, for example, in order to improve fuel efficiency
increases in number. Such an idle reduction vehicle has an issue
that the refrigeration cycle device stops while the vehicle is
stopped (while its engine is stopped), so that comfortableness of
the vehicle interior is impaired. If the engine is restarted even
while the vehicle is stopped to maintain an air-conditioning
feeling, there is also an issue that an improvement in fuel
efficiency is prevented.
[0004] Technologies to resolve these issues are described in Patent
Documents 1 to 5. According to Patent Documents 1 to 5, a heat
exchanger for vehicle interior has a cold storage function to
maintain an air-conditioning feeling even while an engine is
stopped. Accordingly, cold energy is stored while a vehicle is
traveling, and this cold air is used while the vehicle is
stopped.
[0005] In Patent Document 1, it is described that a cold storage
container, in which a cold storage material is sealed, is disposed
on a rear side of a conventional evaporator in an air flow
direction. In Patent Documents 2 to 5, it is described that a cold
storage container having a small capacity is provided adjacent to a
tube which constitutes a refrigerant passage of an evaporator, and
that a cold storage material is sealed in this cold storage
container.
PRIORE ART DOCUMENTS
Patent Documents
[0006] Patent Document 1: JP-A-2009-188518 [0007] Patent Document
2: JP-A-2010-91250 [0008] Patent Document 3: JP-A-2010-112670
[0009] Patent Document 4: JP-A-2010-149814 [0010] Patent Document
5: JP-A-2011-12947
[0011] An evaporator having a cold storage function described in
Patent Documents 2 to 5 accumulates cold air in the cold storage
material through solidification of the cold storage material in the
cold storage container while a compressor for air conditioning is
in operation. While idling is stopped, conversely, a solid cold
storage material releases cold air into the air, being melted.
Accordingly, a temperature change of blown-out air can be limited
to maintain an air-conditioning feeling until the cold storage
material is completely melted.
[0012] However, in case of use under temperature environment where
the cold storage material cannot be solidified while idling is
stopped, a sufficient amount of cold air cannot be accumulated.
Thus, because cold air cannot be released for a long time, there is
an issue that an idle stop time is shortened to maintain an
air-conditioning feeling.
SUMMARY OF INVENTION
[0013] The present disclosure addresses the above issues. Thus, it
is an objective of the present disclosure to provide a cold storage
heat exchanger that can maintain a cold storage function in a wide
range of air temperature.
[0014] To achieve the above-described objective, in one aspect of
the present disclosure, a cold storage heat exchanger for
exchanging heat with air flowing therearound includes a refrigerant
passage in which refrigerant flows, and a cold storage container
that accommodates therein cold storage materials which exchanges
heat with the refrigerant flowing through the refrigerant passage
and retains the amount of heat from the refrigerant. The cold
storage materials having different melting points are accommodated
in the cold storage container. In the cold storage heat exchanger,
the cold storage materials include a cold storage material having a
high melting point, and a cold storage material having a low
melting point. The cold storage material having a high melting
point is disposed on an upstream side of the cold storage material
having a low melting point in a flow direction of air.
[0015] According to the present disclosure, the cold storage
materials having different melting points are divided from each
other and accommodated respectively in the cold storage container.
The cold storage material having a high melting point is disposed
on an upstream side of the cold storage material having a low
melting point in a flow direction of air. Accordingly, when the
temperature of the refrigerant is, for example, equal to or lower
than, the melting point of the high melting point cold storage
material, and is equal to or higher than the melting point of the
low melting point cold storage material, only the high melting
point cold storage material is solidified. As a result, even though
the refrigerant temperature is high, the cold storage can be
carried out. When the refrigerant temperature becomes further low,
all the cold storage materials are solidified. Thus, the cold can
be stored in stages in accordance with the refrigerant temperature.
Therefore, a cold storage function can be maintained in a wider
range of air temperature.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The above and other objects, features and advantages of the
present disclosure will become more apparent from the following
detailed description made with reference to the accompanying
drawings. In the drawings:
[0017] FIG. 1 is a front view illustrating an evaporator 40 of a
first embodiment;
[0018] FIG. 2 is a side view illustrating the evaporator 40 of the
first embodiment;
[0019] FIG. 3 is an enlarged sectional view illustrating a part of
a surface of section taken along a line III-III in FIG. 1;
[0020] FIG. 4 is a sectional view illustrating a cold storage
container 47 of the first embodiment;
[0021] FIG. 5 is a diagram illustrating cold storage states of two
cold storage materials 50a, 50b in the first embodiment;
[0022] FIG. 6 is an enlarged sectional view illustrating a part of
section of an evaporator 40A of a second embodiment;
[0023] FIG. 7 is a sectional view illustrating a cold storage
container 47 of the second embodiment;
[0024] FIG. 8 is a sectional view illustrating a cold storage
container 47C of a third embodiment;
[0025] FIG. 9 is a sectional view illustrating a cold storage
container 47D of a fourth embodiment;
[0026] FIG. 10 is a sectional view illustrating a cold storage
container 47E of a fifth embodiment;
[0027] FIG. 11 is a sectional view illustrating a cold storage
container 47F of a sixth embodiment;
[0028] FIG. 12 is a sectional view illustrating an evaporator 40G
of a seventh embodiment;
[0029] FIG. 13 is a sectional view illustrating an example of an
evaporator 40H of an eighth embodiment;
[0030] FIG. 14 is a sectional view illustrating another example of
an evaporator 40I of the eighth embodiment;
[0031] FIG. 15 is an enlarged sectional view illustrating a part of
an evaporator 40 of a ninth embodiment;
[0032] FIG. 16 is a sectional view illustrating a cold storage
container 47 of the ninth embodiment; and
[0033] FIG. 17 is a diagram illustrating cold storage states of two
cold storage materials 50a, 50b of the ninth embodiment.
EMBODIMENTS FOR CARRYING OUT INVENTION
[0034] Embodiments will be described below with reference to the
drawings. In the embodiments, for a part corresponding to a matter
described in the preceding embodiment, the same reference numeral
may be provided or a single numeral may be added to the preceding
reference numeral, thereby omitting a repeated explanation. In the
embodiments, when a part of configuration is described, the other
part of the configuration is similar to the precedingly-described
embodiment. As well as a combination of the parts specifically
described in the embodiments, a partial combination between the
embodiments is possible unless the combination has a particular
adverse effect.
First Embodiment
[0035] A first embodiment will be described in reference to FIGS. 1
to 5. An evaporator 40 constitutes a refrigeration cycle system
(not shown). The refrigeration cycle system is used for, for
example, an air-conditioning system for a vehicle. The
refrigeration cycle system includes, although not shown, a
compressor, a radiator, a decompressor, and the evaporator 40.
These components are connected through a pipe annularly to
constitute a refrigerant circulation passage. The compressor is
driven by a power source for vehicle traveling. Accordingly, when
the power source stops, the compressor also stops. The compressor
draws in the refrigerant from the evaporator 40, compresses the
refrigerant, and discharges the refrigerant into the radiator. The
radiator cools high-temperature refrigerant. The radiator is also
referred to as a condenser. The decompressor decompresses the
refrigerant cooled by the radiator. The decompressor can be
provided by a fixed throttle, a temperature type expansion valve,
or an ejector. The evaporator 40 evaporates the refrigerant
decompressed by the decompressor to cool a medium. The evaporator
40 cools the air supplied to the vehicle interior.
[0036] The refrigeration cycle system can further include an
internal heat exchange that exchanges heat between high-pressure
side liquid refrigerant and low-pressure side gas refrigerant, or a
tank element of a receiver or accumulator that stores surplus
refrigerant. The power source can be provided by an internal
combustion engine or an electric motor.
[0037] As illustrated in FIGS. 1 and 2, the evaporator 40 is a cold
storage heat exchanger, and includes a refrigerant passage member
branching into more than one portion. This refrigerant passage
member is provided by a passage member made of metal such as
aluminium. The refrigerant passage member is provided by headers 41
to 44 positioned in groups, and refrigerant pipes 45 connecting
together these headers 41 to 44.
[0038] The first header 41 and the second header 42 are grouped and
arranged in parallel with each other with a predetermined distance
therebetween. The third header 43 and the fourth header 44 are
grouped and arranged in parallel with each other with a
predetermined distance therebetween. The refrigerant pipes 45 are
arranged at regular intervals between the first header 41 and the
second header 42. Each refrigerant pipe 45 communicates with the
inside of a corresponding header at its end part. A first heat
exchange part 48 is formed by the first header 41, the second
header 42, and the refrigerant pipes 45 arranged therebetween. The
refrigerant pipes 45 are arranged at regular intervals between the
third header 43 and the fourth header 44.
[0039] Each refrigerant pipe 45 communicates with the inside of a
corresponding header at its end part. A second heat exchange part
49 is formed by the third header 43, the fourth header 44, and the
refrigerant pipes 45 arranged therebetween. As a result, the
evaporator 40 includes the first heat exchange part 48 and the
second heat exchange part 49 which are arranged with two tiers. In
an air flow direction, the second heat exchange part 49 is disposed
on an upstream side, and the first heat exchange part 48 is
disposed on a downstream side.
[0040] A joint (not shown) as a refrigerant inlet is provided at an
end part of the first header 41. The inside of the first header 41
is divided between a first section and a second section with a
partition plate (not shown) provided at nearly the center of the
header 41 in its length direction. The refrigerant pipes 45 are
divided accordingly into a first group and a second group. The
refrigerant is supplied to the first section of the first header
41. The refrigerant is distributed from the first section among the
refrigerant pipes 45 which belong to the first group. The
refrigerant flows into the second header 42 through the first group
to merge together. The refrigerant is distributed from the second
header 42 among the refrigerant pipes 45 which belong to the second
group, again. The refrigerant flows into the second section of the
first header 41 through the second group. As above, in the first
heat exchange part 48, a passage through which the refrigerant
flows in a U-shaped manner is formed.
[0041] A joint (not shown) as a refrigerant outlet is provided at
an end part of the third header 43. The inside of the third header
43 is divided between a first section and a second section with a
partition plate (not shown) provided at nearly the center of the
header 41 in its length direction. The refrigerant pipes 45 are
divided accordingly into a first group and a second group. The
first section of the third header 43 is adjacent to the second
section of the first header 41. The first section of the third
header 43 and the second section of the first header 41 communicate
with each other.
[0042] The refrigerant flows from the second section of the first
header 41 into the first section of the third header 43. The
refrigerant is distributed from the first section among the
refrigerant pipes 45 which belong to the first group. The
refrigerant flows into the forth header 44 through the first group
to merge together. The refrigerant is distributed from the fourth
header 44 among the refrigerant pipes 45 which belong to the second
group, again. The refrigerant flows into the second section of the
third header 43 through the second group. As above, in the second
heat exchange part 49, a passage through which the refrigerant
flows in a U-shaped manner is formed. The refrigerant in the second
section of the third header 43 flows out through the refrigerant
outlet to flow toward the compressor.
[0043] Specific configuration of the refrigerant pipe 45 and so
forth will be described. FIG. 3 illustrates a cold storage
container 47 with its thickness omitted, and cold storage materials
50a, 50b which are hatched. The refrigerant pipe 45 is a porous
pipe having refrigerant passages 45a in which the refrigerant
flows. The refrigerant pipe 45 is also referred to as a flat tube.
This porous pipe can be obtained by an extrusion manufacturing
process. The refrigerant passages 45a extend along a longitudinal
direction of the refrigerant pipe 45, and open at both ends of the
refrigerant pipe 45. The refrigerant pipes 45 are arranged in a
row. In each row, the refrigerant pipes 45 are arranged such that
their principal planes are opposed to each other. The refrigerant
pipes 45 define an air passage 460 for heat exchange with air and
an accommodating part 461 for accommodating the cold storage
container 47 which is described later, between the two refrigerant
pipes 45 adjacent to each other.
[0044] The evaporator 40 includes a fin 46 for increasing a contact
area with the air supplied to the vehicle interior. The fin 46 is
provided by corrugate type fins 46. The fin 46 is disposed in the
air passage 460 defined between the two adjacent refrigerant pipes
45. The fin 46 is thermally bonded to its two adjacent refrigerant
pipes 45. The fin 46 is joined to its two adjacent refrigerant
pipes 45 by a jointing material which is excellent in heat
transfer. Brazing filler metal can be used for the jointing
material. The fin 46 has such a shape that a metal plate such as a
thin aluminium is bent in a corrugated manner, and includes the air
passage 460 which is referred to as a louver.
[0045] The cold storage container 47 will be described below. The
evaporator 40 further includes the cold storage containers 47. The
cold storage container 47 has a flat cylindrical shape. The cold
storage container 47 is closed by crushing the cylinder in its
thickness direction at both ends of the container 47 in its
longitudinal direction, so that a space for accommodating the cold
storage material 50a, 50b is formed in the container 47. The cold
storage container 47 includes a broad principal plane on both its
surfaces. Two main walls which provide these two principal planes
are arranged respectively parallel to the refrigerant pipe 45. The
container 47 is arranged such that the refrigerant pipe 45 is in
contact with at least one surface, in the present embodiment, with
both the surfaces of the cold storage container 47.
[0046] In the cold storage container 47, more than one, in the
present embodiment, two cold storage cases 60 are arranged between
the two adjacent refrigerant pipes 45. The cold storage cases 60
are arranged along a flow direction of drawn air. In other words,
the cold storage cases 60 are arranged such that the cold storage
cases 60 are different between on an upstream side and on a
downstream side in a flow direction of air. The cold storage cases
60 respectively accommodate the cold storage materials 50a, 50b
which are independent and have different melting points.
[0047] As illustrated in FIG. 4, for each of the cold storage cases
60, there is provided one or more sealing port 61, through which
the cold storage material 50a, 50b is sealed. The sealing port 61
is provided at the outer periphery of the cold storage case 60 on
an upstream side (windward side) or on a downstream side (leeward
side) in a flow direction of air. When the cold storage case 60 is
not specified, it is hereinafter referred to as the cold storage
container 47.
[0048] The cold storage container 47 is thermally bonded to the two
refrigerant pipes 45 arranged on both its sides. The cold storage
container 47 is joined to its two adjacent refrigerant pipes 45 by
a jointing material which is excellent in heat transfer. A resin
material such as brazing filler metal or adhesive can be used for
the jointing material. The cold storage container 47 is brazed to
the refrigerant pipes 45. A large amount of brazing filler metal is
arranged between the cold storage container 47 and the refrigerant
pipe 45 for connecting them together by a large cross-sectional
area. This brazing filler metal can be provided by disposing foil
of brazing filler metal between the cold storage container 47 and
the refrigerant pipe 45. As a result, the cold storage container 47
shows good heat conduction between the cold storage container 47
and the refrigerant pipe 45.
[0049] Thickness of each cold storage container 47 is approximately
the same as thickness of the air passage 460. Accordingly, the
thickness of the cold storage container 47 is approximately the
same as thickness of the fin 46. The fin 46 and the cold storage
container 47 can be switched. As a result, an arrangement pattern
of more than one fin 46 and more than one cold storage container 47
can be set with a high degree of freedom.
[0050] The thickness of the cold storage container 47 is obviously
larger than thickness of the refrigerant pipe 45. This
configuration is effective for accommodating the large amount of
the cold storage materials 50a, 50b. The lengths of the cold
storage containers 47 are the same as each other. The length of
arrangement of the two cold storage cases 60 is approximately the
same as that of the fin 46. Accordingly, the cold storage container
47 occupies the almost entire part of the accommodating part 461
defined between its two adjacent refrigerant pipes 45 in a
longitudinal direction of the accommodating part 461. Thus, the
arranged two cold storage cases 60 have the same area in contact
with the refrigerant pipe 45 as each other. In other words, the
arranged two cold storage cases 60 have the same area for
exchanging heat with the refrigerant pipe 45 as each other. The
clearances between the cold storage container 47 and the headers 41
to 44 can be filled with a cut piece of the fin 46 or a filling
material such as resin.
[0051] The refrigerant pipes 45 are arranged nearly at even
intervals. The clearances are formed between these refrigerant
pipes 45. In these clearances, more than one fin 46 and more than
one cold storage container 47 are arranged with predetermined
regularity. A part of the clearances is the air passage 460. The
rest of the clearances is the accommodating part 461 of the cold
storage container 47. For example, 10% to 50% of total intervals
formed between the refrigerant pipes 45 is the accommodating part
461. The cold storage container 47 is arranged in the accommodating
part 461.
[0052] The cold storage containers 47 are arranged generally in an
evenly dispersed manner throughout the entire evaporator 40. The
two refrigerant pipes 45 located on both sides of the cold storage
container 47 define the air passage 460 for heat exchange with the
air on the opposite side from the cold storage container 47. In a
different perspective, the two refrigerant pipes 45 are arranged
between the two fins 46, and furthermore, one cold storage
container 47 including the two cold storage cases 60 which are
paired with each other is disposed between these two refrigerant
pipes 45.
[0053] The cold storage container 47 is made of metal such as
aluminium or aluminum alloy. For example, a material containing
metal whose ionization tendency is lower than hydrogen as its chief
material or component is used for the material of the cold storage
container 47 other than aluminium.
[0054] The cold storage materials 50a, 50b will be described below.
The cold storage materials 50a, 50b are materials that exchange
heat with the refrigerant flowing through the refrigerant passage
45a to retain the amount of heat from the refrigerant. The cold
storage materials 50a, 50b retain the heat from the refrigerant by
solidifying it, and release the retained heat to the outside by
melting it. The cold storage material 50a having a high melting
point is disposed on an upstream side of the cold storage material
50b having a low melting point in a flow direction of air.
Accordingly, in FIG. 3, the cold storage material 50a in the upper
cold storage case 60 has a higher melting point than the cold
storage material 50b in the lower cold storage case 60. An air
thermal load on a windward side of the evaporator 40 tends to be
higher, so that the cold storage material 50a having a high melting
point which is easily solidified despite high temperature is
disposed on a windward side and the cold storage material 50b
having a low melting point is disposed on a leeward side.
[0055] The melting point of the high melting point cold storage
material 50a which is a cold storage material having a high melting
point may be equal to or higher than a cooling temperature zone at
the time of refrigerated air conditioning, i.e., may be 5 degrees
Celsius to 25 degrees Celsius. The melting point of the low melting
point cold storage material 50b which is a cold storage material
having a low melting point may be 0 degrees Celsius to 15 degrees
Celsius. When the melting point of the high melting point cold
storage material 50a ranges from 5 degrees Celsius to 15 degrees
Celsius, the melting point of the low melting point cold storage
material 50b is 0 degrees Celsius or higher, and is lower than the
melting point of the high melting point cold storage material 50a.
Furthermore, the melting point of the high melting point cold
storage material 50a is not higher than a thermal sensing
permissible value (=15 to 17.degree. C.) of blown-out air, and
thus, may be 15.degree. C. or lower. The melting point of the low
melting point cold storage material 50b may range from 0.degree. C.
to 10.degree. C. so that the cold storage material 50b can be
solidified and melted even at low temperature such as during winter
season. The necessary amount of heat of the two cold storage
materials 50a, 50b may be approximately 200 kJ/kg or larger in view
of the volume of the cold storage container 47. Accordingly, the
cold storage capacity necessary at the time of an idling stop can
be ensured.
[0056] Generally, an organic material has a small heat
conductivity, and greatly supercools except paraffin series. In
chemical heat storage, it is chemical stability, a poisonous
substance, corrosiveness, and a reaction facilitator (pressure
holding and agitation necessary). Accordingly, in the present
embodiment, two types of paraffin are used as the cold storage
materials 50a, 50b.
[0057] The paraffin used for the high melting point cold storage
material 50a may have the carbon number of 16 or 15. The paraffin
used for the low melting point cold storage material 50b may have
the carbon number of 15 or 14. When the carbon number of the
paraffin of the high melting point cold storage material 50a is 16,
the carbon number of the low melting point cold storage material
50b may be 15 or 14. When the carbon number of the paraffin of the
high melting point cold storage material 50a is 15, the carbon
number of the paraffin of the low melting point cold storage
material 50b may be 14. Accordingly, even the same paraffin can
have different melting points from each other. In addition, a cold
storage material having hydrate as its main component may be
employed.
[0058] Operation of this embodiment will be described below. When a
request for air conditioning, for example, a request for
refrigerated air conditioning is made by an occupant, the
compressor is driven by the power source. The compressor draws in
the refrigerant from the evaporator 40, compresses the refrigerant,
and discharges the refrigerant. The heat of the refrigerant
discharged from the compressor is released at the radiator. The
refrigerant which has flowed out of the radiator is decompressed by
the decompressor to be supplied to the evaporator 40. The
refrigerant evaporates at the evaporator 40 to cool the cold
storage container 47, and cools its surrounding air via the fin 46.
When the vehicle makes a temporary stop, the power source stops to
reduce energy consumption and the compressor is thus stopped. Then,
the refrigerant of the evaporator 40 gradually loses its cooling
capacity. In this process, the cold storage materials 50a, 50b
radiationally cool gradually to cool the air. In this case, the
heat of air is conducted to the cold storage materials 50a, 50b via
the fin 46, the refrigerant pipe 45, and the cold storage container
47. As a result, even though the refrigeration cycle system is
temporarily stopped, the air can be cooled by the cold storage
materials 50a, 50b. After a while, when the vehicle begins to
travel again, the power source drives the compressor again. Thus,
the refrigeration cycle system cools the cold storage materials
50a, 50b again and the cold storage materials 50a, 50b store the
cold.
[0059] To describe a more specific operation with reference to FIG.
5, when the air-conditioner is in operation under the normal
control at the time of a high load during summer season or at
in-between stages, the refrigerant temperature is lower than the
melting points of both the high melting point cold storage material
50a (A in FIG. 5) and the low melting point cold storage material
50b (B in FIG. 5), so that the cold storage materials 50a, 50b are
solidified to store the cold air. During an idling stop, the
solidified col storage materials release the stored cold air into
the air, being melted to limit a temperature rise of blown-out air,
thereby extending an idle stop time.
[0060] When a fuel saving mode is in use, the refrigerant
temperature is higher than at the time of the high load. In such a
case, when the air-conditioner is in operation, only the high
melting point cold storage material 50a is solidified and can
accumulate the cold air. During an idling stop at the time of the
fuel saving mode, the high melting point cold storage material 50a
releases the accumulated cold air into the air, being melted to
limit a temperature rise of blown-out air, thereby extending an
idle stop time.
[0061] As described above, in the evaporator 40 of the present
embodiment, as the cold storage materials 50a, 50b having different
melting points, in the present embodiment, the two cold storage
materials 50a, 50b are divided from each other and accommodated
respectively in the cold storage container 47. The cold storage
material 50a having a high melting point is disposed on an upstream
side of the cold storage material 50b having a low melting point in
a flow direction of air. Accordingly, when the temperature of the
refrigerant is, for example, equal to or lower than, the melting
point of the high melting point cold storage material 50a, and is
equal to or higher than the melting point of the low melting point
cold storage material 50b, only the high melting point cold storage
material 50a is solidified. As a result, even though the
refrigerant temperature is high, the cold storage can be carried
out. When the refrigerant temperature becomes further low, all the
cold storage materials 50a, 50b are solidified. Thus, the cold can
be stored in stages in accordance with the refrigerant temperature.
Therefore, a cold storage function can be maintained in a wider
range of air temperature.
[0062] The sealing port 61 is provided at the outer periphery of
the cold storage case 60 on an upstream side or on a downstream
side in a flow direction of air. Accordingly, the sealing port 61
is not provided in the air passage 460, so that the sealing port 61
can be prevented from becoming a draft resistance.
Second Embodiment
[0063] A second embodiment will be described in reference to FIGS.
6 and 7. The present embodiment is characterized in that cold
storage cases 60A are arranged to be in contact with each other.
Because of such a configuration in which the cold storage cases 60A
are in contact, the space can be used more effectively.
Accordingly, the amount of cold storage materials 50a, 50b, with
which a cold storage container 47 can be filled, can be made large.
Operation and effects of the other configuration are similar to the
above-described first embodiment.
Third Embodiment
[0064] A third embodiment will be described in reference to FIG. 8.
The present embodiment is characterized in that the inside of a
cold storage container 47C is divided by a partition 70, and that
cold storage materials 50a, 50b having different melting points are
accommodated respectively in the divided spaces. One sealing port
61, through which the cold storage material 50a, 50b is sealed, is
provided for this cold storage container 47C. Accordingly, two
types of the cold storage materials 50a, 50b are sealed through the
one sealing port 61. As a result, the configuration is simplified,
and is easily handled as the cold storage container 47C. The
sealing port 61 is provided at the outer periphery of the cold
storage container 47C on an upstream side or on a downstream side
in a flow direction of air, and is provided on a leeward side in
the present embodiment. Because of such a configuration, the space
can be used more effectively. Accordingly, the amount of the cold
storage materials 50a, 50b, with which the cold storage container
47C can be filled, can be made large. Operation and effects of the
other configuration are similar to the above-described first
embodiment.
Fourth Embodiment
[0065] A fourth embodiment will be described in reference to FIG.
9. The present embodiment is characterized in that cold storage
cases 60D are arranged to be away from each other and that both two
sealing ports 61 are on the same side. As a result of such a
configuration as well, operation and effects similar to the above
first embodiment can be achieved.
Fifth Embodiment
[0066] A fifth embodiment will be described in reference to FIG.
10. The present embodiment is characterized in that cold storage
cases 60E are formed integrally to be in contact with each other
and that both two sealing ports 61 are on the same side. As a
result of such a configuration as well, operation and effects
similar to the above second embodiment can be achieved.
Sixth Embodiment
[0067] A sixth embodiment will be described in reference to FIG.
11. The present embodiment is characterized in that cold storage
cases 60F are formed integrally to be in contact with each other
and that both two sealing ports 61 are on the same side.
Furthermore, one of the sealing ports 61 is configured as a pipe
61F. As a result of such a configuration as well, operation and
effects similar to the above second embodiment can be achieved.
Seventh Embodiment
[0068] A seventh embodiment will be described in reference to FIG.
12. The present embodiment is characterized in that cold storage
cases 60G are arranged on one side of a refrigerant passage 45a.
The configuration illustrated in FIG. 12 is of a "drawn cup type".
As a result of the arrangement on one side of a refrigerant passage
45a, the space can be conserved as a whole. As a result of such a
configuration as well, operation and effects similar to the above
first embodiment can be achieved.
Eighth Embodiment
[0069] An eighth embodiment will be described in reference to FIGS.
13 and 14. The present embodiment is also characterized in that
cold storage cases 60H, 60I are arranged on one side of a
refrigerant passage 45a similar to the above seventh embodiment.
The two cold storage cases 60H, 601 extend along a flow direction
of air and are arranged along the flow direction of air. FIG. 13
illustrates that the cold storage cases 60H are arranged at
intervals in the flow direction of air. FIG. 14 illustrates that
the cold storage cases 601 are arranged to be in contact with each
other in the flow direction of air. In this manner, by arranging
the cold storage cases 60H, 601 only on one side of the refrigerant
passage 45a, the space can be conserved as a whole. Moreover,
operation and effects similar to the above first embodiment can be
achieved.
Ninth Embodiment
[0070] A ninth embodiment will be described in reference to FIGS.
15 to 17. As illustrated in FIGS. 15 and 16, the present embodiment
is characterized in that one type of a cold storage material 50 is
accommodated in each cold storage container 47J. In addition, the
present embodiment is characterized in that a high melting point
cold storage material 50a is accommodated in one of the adjacent
cold storage containers 47J, and a low melting point cold storage
material 50b is accommodated in the other one of the adjacent cold
storage containers 47J. The present embodiment can be applied to a
case where the cooling capacity of an evaporator 40J is
sufficiently high.
[0071] Accordingly, the cold storage container 47J accommodating
the high melting point cold storage material 50a, and the cold
storage container 47J accommodating the low melting point cold
storage material 50b are arranged alternately between refrigerant
pipes 45. FIGS. 15 and 16 illustrate the cold storage container 47J
in which the high melting point cold storage material 50a is
accommodated.
[0072] To describe a specific operation with reference to FIG. 17,
when the air-conditioner is in operation under the normal control
at the time of a high load during summer season or at in-between
stages, the refrigerant temperature is lower than the melting
points of both the high melting point cold storage material 50a (A
in FIG. 17) and the low melting point cold storage material 50b (B
in FIG. 17), so that the cold storage materials 50a, 50b are
solidified to store the cold air. During an idling stop, the
solidified cold storage materials release the stored cold air into
the air, being melted to limit a temperature rise of blown-out air,
thereby extending an idle stop time.
[0073] When a fuel saving mode is in use, the refrigerant
temperature is higher than at the time of the high load. In such a
case, when the air-conditioner is in operation, only the high
melting point cold storage material 50a is solidified and can
accumulate the cold air. During an idling stop at the time of the
fuel saving mode, the high melting point cold storage material 50a
releases the accumulated cold air into the air, being melted to
limit a temperature rise of blown-out air, thereby extending an
idle stop time.
[0074] In the above-described first embodiment, if the temperature
on the windward side of the evaporator 40 is high and the low
melting point cold storage material 50b is not solidified, the high
melting point cold storage material 50a can be disposed on the
windward side, and the low melting point cold storage material 50b
can be disposed on the leeward side. However, if the cooling
capacity of the evaporator 40J is sufficiently high and the
temperature of the evaporator 40J decreases almost evenly in a flow
direction of air as in the present embodiment, the high melting
point cold storage material 50a does not need to be disposed only
on the windward side. Thus, by disposing the single cold storage
container 47J along the flow direction of air as in the present
embodiment, operation and effects similar to the above first
embodiment can be achieved.
[0075] In the present embodiment, the cold storage containers 47J
having different melting points are arranged alternately (high
melting point--low melting point--high melting point . . . ).
However, the present disclosure is not limited to this alternate
arrangement. For example, instead of the one-by-one alternate
arrangement, the cold storage containers 47J may be arranged
alternately two by two (high melting point--high melting point--low
melting point--low melting point--high melting point--high melting
point . . . ), or may be arranged alternately three by three. In
other words, at least a part of the cold storage material 50a of
the cold storage materials 50a, 50b accommodated in the cold
storage containers 47J may have a different melting point from the
cold storage material 50b accommodated in another cold storage
container. Accordingly, the cold storage container 47J
accommodating the high melting point cold storage material 50a, and
the cold storage container 47J accommodating the low melting point
cold storage material 50b do not need to be the same in number.
Depending on a temperature distribution of the refrigerant flowing
through the evaporator 40J, the melting point and volume of the
cold storage material 50 accommodated in each cold storage
container 47J may be appropriately selected.
[0076] The embodiments have been described above. The present
disclosure is not by any means limited to the above embodiments,
and can be embodied in various modifications without departing from
the scope of the present disclosure.
[0077] The structures of the above-described embodiments are only
exemplifications, and the scope of the present disclosure is not
limited to these descriptions. The scope of the present disclosure
is recited in the scope of claims, and includes all the
modifications within a meaning and a range equivalent to the
recital of the scope of claims.
[0078] In the above first and ninth embodiments, there are two
types of the cold storage materials 50a, 50b. However, they do not
need to be of two types, and may be of three or more types.
Accordingly, the cold can be stored further in stages, and the
present disclosure can be applied to a wider air-conditioning
temperature range.
[0079] The refrigerant pipe 45 can be provided by a porous
extrusion pipe or a pipe that is obtained by cylindrically bending
a plate material including dimples. Furthermore, the fin can be
eliminated. Such a heat exchanger is also referred to as a
finless-type heat exchanger. The heat exchange with air may be
promoted by providing, for example, a ridge extending out of the
refrigerant pipe instead of the fin.
[0080] The cold storage case 60 does not need to be disposed at the
outer periphery of the refrigerant pipe 45, and the cold storage
case may be disposed in the refrigerant passage. There may be one
cold storage case 60. For example, the heat exchanger may be
disposed transversely, and a cold storage material having a high
melting point and a high specific gravity, and a cold storage
material having a low melting point and a low specific gravity may
be arranged to be sealed in one container. Accordingly, the cold
storage material having a high melting point can exist on an
upstream side in a flow direction of air without preparing more
than one cold storage case for separation.
[0081] In the above-described first embodiment, there are more than
one type of cold storage materials. However, a mixture of the cold
storage materials may be used.
[0082] The present disclosure can be applied to an evaporator
having various flow paths. For example, the present disclosure may
be applied to an evaporator such as one direction type evaporator
or a front-rear U-turn type evaporator instead of the right-left
U-turn type as in the first embodiment.
[0083] Furthermore, the present disclosure may be applied to a
refrigeration cycle system for refrigeration, for heating, or for
hot water supply, for example. Moreover, the present disclosure may
be applied to a refrigeration cycle system including an
ejector.
[0084] Additionally, an inner fin may be provided in the cold
storage container 47. In the case of such a configuration, an
opening, from which a top part of the inner fin is exposed, may be
provided at an outer shell of the container 47, and the top part of
the inner fin may be joined directly to the refrigerant pipe.
[0085] While the present disclosure has been described with
reference to embodiments thereof, it is to be understood that the
disclosure is not limited to the embodiments and constructions. The
present disclosure is intended to cover various modification and
equivalent arrangements. In addition, while the various
combinations and configurations, other combinations and
configurations, including more, less or only a single element, are
also within the spirit and scope of the present disclosure.
* * * * *