U.S. patent application number 14/890562 was filed with the patent office on 2016-05-12 for hydrogen gas cooling method and hydrogen gas cooling system.
This patent application is currently assigned to KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). The applicant listed for this patent is KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.). Invention is credited to Yuji KURISHIRO, Yasutake MIWA, Koji NOISHIKI, Kunihiko SHIMIZU.
Application Number | 20160131434 14/890562 |
Document ID | / |
Family ID | 52431616 |
Filed Date | 2016-05-12 |
United States Patent
Application |
20160131434 |
Kind Code |
A1 |
NOISHIKI; Koji ; et
al. |
May 12, 2016 |
HYDROGEN GAS COOLING METHOD AND HYDROGEN GAS COOLING SYSTEM
Abstract
A hydrogen gas cooling method is provided. The method includes a
preparation step and a cooling step. In the preparation step, a
heat exchanger that contains a layered body of a first layer and a
second layer is prepared. The first layer has a plurality of first
micro channels, and the second layer has a plurality of second
micro channels. In the cooling step, hydrogen gas is cooled by
exchanging heat between the hydrogen gas flowing in the first
channels with brine flowing in the second channels.
Inventors: |
NOISHIKI; Koji;
(Takasago-shi, JP) ; MIWA; Yasutake;
(Takasago-shi, JP) ; SHIMIZU; Kunihiko; (Kobe-shi,
JP) ; KURISHIRO; Yuji; (Kobe-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) |
Kobe-shi, Hyogo |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA KOBE SEIKO SHO
(KOBE STEEL, LTD.)
Kobe-shi, Hyogo
JP
|
Family ID: |
52431616 |
Appl. No.: |
14/890562 |
Filed: |
July 17, 2014 |
PCT Filed: |
July 17, 2014 |
PCT NO: |
PCT/JP2014/069030 |
371 Date: |
November 11, 2015 |
Current U.S.
Class: |
165/296 ;
165/166 |
Current CPC
Class: |
F28F 3/086 20130101;
F28D 9/0037 20130101; H01M 8/04074 20130101; Y02E 60/50 20130101;
F28F 7/02 20130101; Y02T 10/30 20130101; F02M 21/0206 20130101;
F28D 9/0093 20130101; Y02E 60/32 20130101 |
International
Class: |
F28D 9/00 20060101
F28D009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2013 |
JP |
2013-159513 |
Claims
1. A hydrogen gas cooling method, the method comprising: preparing
a heat exchanger, which comprises a stacked body comprising a first
layer and a second layer stacked upon one another, wherein the
first layer comprises a plurality of first flow passages that are
fine flow passages and the second layer comprises a plurality of
second flow passages that are fine flow passages; and cooling a
hydrogen gas which is allowed to flow through each of the first
flow passages while allowing a brine that is a non-evaporative
antifreeze and has a temperature lower than the hydrogen gas to
flow through each of the second flow passages to perform heat
exchange between the hydrogen gas flowing through the first flow
passages and the brine flowing through the second flow passages,
wherein in said cooling, the hydrogen gas is allowed to flow
through each of the first flow passages such that the hydrogen gas
flowing through each of the first flow passages moves from one side
to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer while
the brine is allowed to flow through each of the second flow
passages such that the brine flowing through each of the second
flow passages moves from the other side to the one side in the
particular direction, and a temperature and a flow rate of the
brine fed into each of the second flow passages are controlled such
that a temperature of the brine at a feed-out port of the second
flow passages is higher than a temperature of the hydrogen gas at a
feed-out port of the first flow passages.
2. The hydrogen gas cooling method according to claim 1, wherein in
said preparing, the heat exchanger is a heat exchanger comprising a
stacked body in an interior of which each of the first flow
passages and each of the second flow passages are formed to each
have a meandering shape, and in said cooling, the hydrogen gas is
allowed to flow along the meandering shape of each of the first
flow passages through each of the first flow passages, and the
brine is allowed to flow along the meandering shape of each of the
second flow passages through each of the second flow passages.
3. The hydrogen gas cooling method according to claim 1, wherein in
said cooling, the flow rate of the brine fed into each of the
second flow passages is controlled such that the temperature of the
brine at the feed-out port of the second flow passages is higher by
at least 10.degree. C. than the temperature of the brine at an
inflow port of the second flow passages.
4. A hydrogen gas cooling system comprising: a cooler that cools a
brine that is a non-evaporative antifreeze; a heat exchanger that
is connected to the cooler such that the brine circulates between
the heat exchanger and the cooler, and allows a hydrogen gas to be
subjected to heat exchange with the brine supplied from the cooler,
thereby cooling the hydrogen gas; a pump that delivers the brine
that has been cooled by the cooler from the cooler to the heat
exchanger; and a control unit that controls a temperature of the
brine, wherein the heat exchanger comprises a stacked body in which
a first layer in which a plurality of first flow passages that are
fine flow passages into which the hydrogen gas is fed and flows
therethrough are arranged and a second layer in which a plurality
of second flow passages that are fine flow passages into which the
brine is fed and flows therethrough are arranged are stacked upon
one another, and allows heat exchange between the hydrogen gas
flowing through the first flow passages and the brine flowing
through the second flow passages to be performed, each of the first
flow passages comprises a first inflow port that receives the
hydrogen gas and a first feed-out port that discharges the hydrogen
gas, and the first inflow port and the first feed-out port are
disposed such that the hydrogen gas that is fed from the first
inflow port into the first flow passages and flows through the
first flow passages toward the first feed-out port moves from one
side to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer, each of
the second flow passages comprises a second inflow port that
receives the brine and a second feed-out port that discharges the
brine, and the second inflow port and the second feed-out port are
disposed such that the brine that is fed from the second inflow
port into the second flow passages and flows through the second
flow passages toward the second feed-out port moves from the other
side to the one side in the particular direction, and the control
unit controls an operation of the cooler and a flow rate of the
brine that the pump delivers, such that the temperature of the
brine at the second feed-out port is higher than a temperature of
the hydrogen gas at the first feed-out port.
5. The hydrogen gas cooling system according to claim 4, further
comprising: a first feed-out port temperature detection portion
that detects the temperature of the hydrogen gas at the first
feed-out port; and a second feed-out port temperature detection
portion that detects the temperature of the brine at the second
feed-out port, wherein based on the temperature detected by the
first feed-out port temperature detection portion and the
temperature detected by the second feed-out port temperature
detection portion, the control unit controls the flow rate of the
brine that the pump delivers.
6. The hydrogen gas cooling system according to claim 4, wherein
each of the first flow passages and each of the second flow
passages are formed in the stacked body to each have a meandering
shape.
7. The hydrogen gas cooling system according to claim 4, wherein
the control unit allows the pump to deliver the brine such that the
brine flows through each of the second flow passages at such a flow
rate that the temperature of the brine at the second feed-out port
is higher by at least 10.degree. C. than the temperature of the
brine at the second inflow port.
Description
TECHNICAL FIELD
[0001] The present invention relates to a hydrogen gas cooling
method and a hydrogen gas cooling system.
BACKGROUND ART
[0002] In a hydrogen station in which a hydrogen gas is supplied to
a fuel cell vehicle, to enhance an efficiency of filling the fuel
cell vehicle with the hydrogen gas, the hydrogen gas is compressed
to have a high pressure before the filling. In filling a tank of
the fuel cell vehicle with this compressed hydrogen gas, a
compression heat is generated in accordance with an increase of a
pressure in the tank. Accordingly, to avoid a temperature increase
of the tank due to the compression heat, the hydrogen gas that has
been allowed to have a high pressure in the hydrogen station is
cooled and then supplied to the fuel cell vehicle. Patent Documents
1 and 2 as described below disclose an example of cooling methods
and cooling systems for cooling a hydrogen gas before supplying the
same to a fuel cell vehicle in this manner.
[0003] In Patent Document 1 as described below, a cooling system
including a heat exchanger including: a container having a filled
bath in the interior; a gas flow passage; and a heat transfer
medium flow passage is used. A filled layer is filled with a heat
transfer medium containing metal powders. The gas flow passage and
the heat transfer medium flow passage are led into the filled layer
from the exterior of the container to have a spiral shape. The gas
flow passage and the heat transfer medium flow passage are arranged
adjacent to each other in such a manner as to lie along each other.
A hydrogen gas is allowed to flow through the gas flow passage. A
low-temperature heat transfer medium different from the heat
transfer medium filled into the filled bath is allowed to flow
through the heat transfer medium flow passage. While flowing
through the gas flow passage, the hydrogen gas is subjected to heat
exchange directly with the heat transfer medium flowing through the
heat transfer medium flow passage, or through the heat transfer
medium in the filled bath, thereby being cooled.
[0004] Moreover, in Patent Document 2 as described below, a cooling
system including a heat exchanger including a dual pipe through
which a hydrogen gas and a refrigerant are allowed to flow is used.
In this cooling system, to improve a heat transfer efficiency, the
dual pipe in which a pressure in a hydrogen supply passage and a
pressure in a refrigerant supply passage are configured to be
substantially the same is used. Thereby, a pipe wall of an inner
pipe between both supply passages are allowed to be thin. As a
result, heat transfer resistance of the heat exchanger decreases
while the heat exchanger is downsized.
[0005] In a hydrogen gas cooling method disclosed in Patent
Document 1 as described above, the filled bath is required to be
filled with the heat transfer medium in large amount. Accordingly,
an amount of use of the heat transfer medium increases. Meanwhile,
since heat resistance of the heat transfer medium in large amount
filled into the filled bath is large, the heat transfer medium that
flows through the heat transfer medium flow passage is required to
have a further low temperature to perform sufficient cooling of a
hydrogen gas according to the cooling method disclosed in Patent
Document 1 as described above. Accordingly, an energy required for
cooling this heat transfer medium increases.
[0006] On the other hand, in a hydrogen gas cooling method
disclosed in Patent Document 2 as described above, an amount of use
of the refrigerant as heat transfer medium can be reduced in
comparison with the cooling method disclosed in Patent Document 1
as described above. However, to increase an amount of hydrogen gas
cooling treatment, for example, increasing the number of the dual
pipe is required. If the number of the dual pipe increases, the
heat exchanger enlarges. Moreover, Patent Document 2 as described
above indicates that, to improve a heat transfer efficiency, a
pressure in the hydrogen supply passage and a pressure in the
refrigerant supply passage are configured to be substantially the
same, whereas, in practice, when a high-pressure hydrogen gas is
filled into a fuel cell vehicle, a pressure of the hydrogen gas
changes every moment. Consequently, even if a pressure control of
the hydrogen gas that flows through the hydrogen supply passage is
performed, in practice, a pressure difference between the hydrogen
supply passage and the refrigerant supply passage increases. Thus,
determining a wall thickness of the pipe having a safety factor in
consideration of this increased pressure difference is required.
Consequently, the wall thickness of the pipe is eventually obliged
to be large, and as a result, heat resistance of the pipe
increases. In this case, if the refrigerant that flows through the
refrigerant supply passage in an outer pipe fails to have a further
low temperature, the hydrogen gas that flows through the hydrogen
supply passage in the inner pipe cannot be sufficiently cooled.
Accordingly, an energy required for cooling the refrigerant
increases.
CITATION LIST
Patent Documents
[0007] Patent Document 1: JP 2010-121657 A
[0008] Patent Document 2 : JP 2011-80495 A
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to reduce an amount of
use of a brine as a heat transfer medium that is used for cooling a
hydrogen gas, and be capable of suppressing an increase of an
energy required for cooling the brine and sufficiently cooling the
hydrogen gas, while both downsizing a heat exchanger and ensuring
an amount of hydrogen gas cooling treatment.
[0010] A hydrogen gas cooling method according to an aspect of the
present invention is a hydrogen gas cooling method using a brine
that is a non-evaporative antifreeze, the method including: a
preparation step of preparing a heat exchanger including a stacked
body in which a first layer in which a plurality of first flow
passages that are fine flow passages are arranged and a second
layer in which a plurality of second flow passages that are fine
flow passages are arranged are stacked upon one another; and a
cooling step in which a hydrogen gas is allowed to flow through
each of the first flow passages while a brine having a temperature
lower than the hydrogen gas is allowed to flow through each of the
second flow passages to perform heat exchange between the hydrogen
gas flowing through the first flow passages and the brine flowing
through the second flow passages, thereby cooling the hydrogen gas,
in which, in the cooling step, the hydrogen gas is allowed to flow
through each of the first flow passages such that the hydrogen gas
flowing through each of the first flow passages moves from one side
to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer while
the brine is allowed to flow through each of the second flow
passages such that the brine flowing through each of the second
flow passages moves from the other side to the one side in the
particular direction, and a temperature and a flow rate of the
brine fed into each of the second flow passages are controlled such
that the temperature of the brine at a feed-out port of the second
flow passages is higher than a temperature of the hydrogen gas at a
feed-out port of the first flow passages.
[0011] A hydrogen gas cooling system according to another aspect of
the present invention is a hydrogen gas cooling system using a
brine that is a non-evaporative antifreeze, the system including: a
cooler that cools the brine; a heat exchanger that is connected to
the cooler such that the brine circulates between the heat
exchanger and the cooler, and allows a hydrogen gas to be subjected
to heat exchange with the brine supplied from the cooler, thereby
cooling the hydrogen gas; a pump that delivers the brine that has
been cooled by the cooler from the cooler to the heat exchanger;
and a control unit that controls a temperature of the brine, in
which the heat exchanger includes a stacked body in which a first
layer in which a plurality of first flow passages that are fine
flow passages into which the hydrogen gas is fed and flows
therethrough are arranged and a second layer in which a plurality
of second flow passages that are fine flow passages into which the
brine is fed and flows therethrough are arranged are stacked upon
one another, and allows heat exchange between the hydrogen gas
flowing through the first flow passages and the brine flowing
through the second flow passages to be performed, each of the first
flow passages includes a first inflow port that receives the
hydrogen gas and a first feed-out port that discharges the hydrogen
gas, and the first inflow port and the first feed-out port are
disposed such that the hydrogen gas that is fed from the first
inflow port into the first flow passages and flows through the
first flow passages toward the first feed-out port moves from one
side to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer, each of
the second flow passages includes a second inflow port that
receives the brine and a second feed-out port that discharges the
brine, and the second inflow port and the second feed-out port are
disposed such that the brine that is fed from the second inflow
port into the second flow passages and flows through the second
flow passages toward the second feed-out port moves from the other
side to the one side in the particular direction, and the control
unit controls an operation of the cooler and a flow rate of the
brine that the pump delivers, such that the temperature of the
brine at the second feed-out port is higher than a temperature of
the hydrogen gas at the first feed-out port.
BRIEF DESCRIPTION OF DRAWINGS
[0012] [FIG. 1] FIG. 1 is a diagram schematically illustrating an
entire configuration of a hydrogen gas cooling system according to
a first embodiment of the present invention.
[0013] [FIG. 2] FIG. 2 is a front view of a heat exchanger, as
viewed from one side in a base plate stacking direction, that is
used in the hydrogen gas cooling system according to the first
embodiment of the present invention
[0014] [FIG. 3] FIG. 3 is a side view of the heat exchanger
illustrated in FIG. 2 as viewed from the right side in FIG. 2.
[0015] [FIG. 4] FIG. 4 is a partial cross-sectional view of a
stacked body of the heat exchanger illustrated in FIG. 3.
[0016] [FIG. 5] FIG. 5 is a schematic plan view of a first base
plate that forms a first flow passage in the stacked body of the
heat exchanger illustrated in FIG. 3.
[0017] [FIG. 6] FIG. 6 is a schematic plan view of a second base
plate that forms second flow passages in the stacked body of the
heat exchanger illustrated in FIG. 3.
DESCRIPTION OF EMBODIMENTS
[0018] Hereinafter, embodiments of the present invention will be
described with reference to the drawings.
[0019] First, a configuration of a cooling system that is used for
a hydrogen gas cooling method according to an embodiment of the
present invention with reference to FIGS. 1-6.
[0020] This cooling system is used, for example, for cooling a
hydrogen gas that is supplied to a fuel cell vehicle 90 (see FIG.
1) in a hydrogen station. In the hydrogen station, to enhance an
efficiency of filling the fuel cell vehicle 90 with the hydrogen
gas, the hydrogen gas is compressed to have a high pressure and
then supplied to the fuel cell vehicle 90. In accordance with this
compression of the hydrogen gas, a compression heat is generated.
To avoid a temperature increase of the hydrogen gas due to this
compression heat, the cooling system according to this embodiment
is to cool the compressed high-pressure hydrogen gas to a low
temperature before filling the fuel cell vehicle 90 with the
same.
[0021] The cooling system according to this embodiment includes, as
illustrated in FIG. 1, a cooler 2, a tank 4, a first pump 6, a
second pump 8, a heat exchanger 10, a control unit 58, a second
inflow port temperature detection portion 60, a second feed-out
port temperature detection portion 62, and a first feed-out port
temperature detection portion 64.
[0022] The cooler 2 is a device for cooling a brine. The cooler 2
is configured to be capable of changing a cooling power to cool the
brine. The cooler 2 receives a control signal from the control unit
58 as described below. The cooler 2 changes the cooling power in
accordance with the received control signal. In other words, when
the received control signal indicates an increase of the cooling
power, the cooler 2 increases the cooling power in accordance with
this indication, while, when the received control signal indicates
a decrease of the cooling power, the cooler 2 decreases the cooling
power in accordance with this indication. The brine is a
non-evaporative antifreeze. As the brine, for example, an ethylene
glycol solution, a fluorinated liquid, or the like, may be
used.
[0023] The cooler 2 includes a feeding portion 2a and a discharge
portion 2b. The feeding portion 2a is a portion into which the
brine that has been subjected to heat exchange with the hydrogen
gas in the heat exchanger 10 so as to have an increased temperature
is fed. The discharge portion 2b is a portion for discharging the
brine that has been cooled by the cooler 2. The cooler 2 allows the
brine that has been fed from the feeding portion 2a into the cooler
2 to be subjected to heat exchange with a refrigerant, such as a
low-temperature hydrochlorofluorocarbon, thereby cooling the brine.
The cooler 2 discharges the cooled brine from the discharge portion
2b. The cooler 2 is configured to be capable of changing a
temperature of the refrigerant. The cooler 2 changes the
temperature of the refrigerant, thereby changing the cooling power
for cooling the brine. In other words, when the control signal that
has been received from the control unit 58 indicates an increase of
the cooling power, the cooler 2 decreases the temperature of the
refrigerant to increase the cooling power, while, when the control
signal that has been received from the control unit 58 indicates a
decrease of the cooling power, the cooler 2 increases the
temperature of the refrigerant to decrease the cooling power. The
brine at, for example, -30.degree. C. is fed into the cooler 2. The
cooler 2 cools the brine that has been fed thereinto to, for
example, -40.degree. C. or lower.
[0024] The tank 4 stores the brine. In the tank 4, a first
reservoir chamber 12 and a second reservoir chamber 14 are
provided. The first reservoir chamber 12 stores the cooled brine
that has been discharged from the cooler 2. The second reservoir
chamber 14 stores the brine that has been subjected to heat
exchange and discharged from the heat exchanger 10.
[0025] The first reservoir chamber 12 is connected through a pipe
18 to the discharge portion 2b of the cooler 2, while connected
through a pipe 20 to a supply header 28, as described below, of the
heat exchanger 10. The second reservoir chamber 14 is connected
through a pipe 22 to a discharge header 30, as described below, of
the heat exchanger 10, while connected through a pipe 24 to the
feeding portion 2a of the cooler 2.
[0026] A partition wall 16 is provided between the first reservoir
chamber 12 and the second reservoir chamber 14. This partition wall
16 prevents the brine that has been cooled and is stored in the
first reservoir chamber 12 and the brine that has been subjected to
heat exchange and is stored in the second reservoir chamber 14 from
being mixed with each other. Moreover, the partition wall 16 is
made of a high heat-insulating material. The partition wall 16
prevents heat exchange between the brine stored in the first
reservoir chamber 12 and the brine stored in the second reservoir
chamber 14 from occurring.
[0027] The first pump 6 is provided to the pipe 20 connected to a
feed-out portion of the first reservoir chamber 12. The first pump
6 sucks the brine stored in the first reservoir chamber 12 while
delivering the same to the heat exchanger 10. This first pump 6 is
configured to be capable of changing a flow rate of delivering the
brine per unit time (hereinafter simply referred to as delivery
flow rate). The first pump 6 receives a control signal from the
control unit 58 as described below. The first pump 6 changes the
flow rate of delivering the brine in accordance with the received
control signal. In other words, when the received control signal
indicates an increase of the delivery flow rate, the first pump 6
increases the flow rate of delivering the brine per unit time in
accordance with this indication, while, when the received control
signal indicates a decrease of the delivery flow rate, the first
pump 6 decreases the flow rate of delivering the brine per unit
time in accordance with this indication.
[0028] The second pump 8 is provided to the pipe 24 connected to a
feed-out portion of the second reservoir chamber 14. The second
pump 8 sucks the brine stored in the second reservoir chamber 14
while delivering the same to the feeding portion 2a of the cooler
2. This second pump 8 is configured to be capable of changing the
flow rate of delivering the brine per unit time.
[0029] The heat exchanger 10 allows the hydrogen gas that has been
compressed by the compressor 100 to have a high pressure to be
subjected to heat exchange with the low-temperature brine, thereby
cooling the hydrogen gas. This heat exchanger 10 includes a
multitude of microchannels (fine flow passages). The heat exchanger
10 is a so-called microchannel heat exchanger in which, while
fluids are allowed to respectively flow through the microchannels,
heat exchange among the fluids is performed.
[0030] The heat exchanger 10 includes a stacked body 26 in the
interior of which a multitude of flow passages are provided, the
supply header 28 for supplying the brine to second flow passages
34, as described below, in the stacked body 26, and the discharge
header 30 for discharging the brine from the second flow passages
34 as described below.
[0031] The stacked body 26 has a rectangular parallelepiped
external shape. In the interior of the stacked body 26, a multitude
of first flow passages 32 and the multitude of second flow passages
34 are provided as illustrated in FIG. 4. Each of the first flow
passages 32 and each of the second flow passages 34 are
microchannels (fine flow passages). The first flow passages 32
allow the hydrogen gas to flow. The second flow passages 34 allow
the brine for cooling the hydrogen gas to flow.
[0032] The stacked body 26 is made of a plurality of first base
plates 38, a plurality of second base plates 40, and a pair of end
plates 42, as illustrated in FIG. 3. Specifically, the first base
plates 38 and the second base plates 40 are alternately stacked
upon one another, and upon both ends in a stacking direction
thereof, the pair of end plates 42 are separately stacked, whereby
the stacked body 26 is formed. In the stacked body 26, the second
base plates 40 are stacked upon corresponding both sides in a
thickness direction of the first base plates 38. The plurality of
first flow passages 32 are arranged in each of the first base
plates 38. The plurality of second flow passages 34 are arranged in
each of the second base plates 40. Each of the base plates 38, 40
is a thin flat plate made of, for example, stainless steel, or the
like. The stacked base plates 38, 40 are integrally formed by
diffusion bonding plate surfaces thereof together that are in
contact with each other. Note that the first base plates 38 are an
example of first layers of the present invention. The second base
plates 40 are an example of second layers of the present
invention.
[0033] In one of the plate surfaces in the thickness direction of
each of the first base plates 38 (see FIG. 5), a plurality of first
flow passage groove portions 48 for forming the plurality of first
flow passages 32 are formed. Note that FIG. 5 illustrates an
external shape of the entirety of each of the plurality of first
flow passage groove portions 48 formed in each of the first base
plates 38. In other words, in FIG. 5, illustration of each of the
first flow passage groove portions 48 is omitted, but, in practice,
the plurality of first flow passage groove portions 48 are arranged
parallel to each other in the external shape as illustrated in FIG.
5. Openings of the plurality of first flow passage groove portions
48 formed in the one of the plate surfaces of each of the first
base plates 38 are sealed by one of the second base plates 40 that
is stacked on this plate surface. The plurality of first flow
passage groove portions 48 in which these openings are sealed form
the plurality of first flow passages 32 that are arranged on one of
plate surface sides of each of the first base plates 38 while lying
along this one of the plate surfaces.
[0034] A first inflow port 50 of each of the first flow passages 32
is formed at a location that is adjacent to one end of the stacked
body 26 in a longitudinal direction of the first base plates 38
(adjacent to an upper end of the stacked body 26) while adjacent to
one end of the stacked body 26 in a width direction of the first
base plates 38. This first inflow port 50 is a portion for
receiving the hydrogen gas. The first inflow port 50 is made of a
through hole that penetrates each of the base plates 38, 40 and one
of the pair of end plates 42 at the same location in the thickness
direction to communicate therewith. Thereby, the first inflow port
50 continues in the stacking direction of the base plates 38, 40
and is a hole that opens at a plate surface of the one of the end
plates 42 at a front side. Moreover, the plurality of first flow
passages 32 formed in each of the first base plates 38 are all
connected to this first inflow port 50. In other words, the first
inflow port 50 is a feeding port of the hydrogen gas that is common
to all the first flow passages 32 provided in the stacked body
26.
[0035] A first feed-out port 52 of each of the first flow passages
32 is formed at a location that is adjacent to an end portion of
the stacked body 26 at a side opposite to the first inflow port 50
in the longitudinal direction and the width direction of the first
base plates 38. This first feed-out port 52 is a portion for
discharging the hydrogen gas that has flown through each of the
first flow passages 32. Similarly to the first inflow port 50, the
first feed-out port 52 is made of a through hole that penetrates
each of the base plates 38, 40 and the one of the end plates 42 at
the same location in the thickness direction to communicate
therewith. Moreover, similarly to the first inflow port 50, the
first feed-out port 52 is a discharge port of the hydrogen gas that
is common to all the first flow passages 32 provided in the stacked
body 26.
[0036] Each of the first flow passages 32 has a meandering shape in
which a portion that linearly extends from one side to the other
side in the width direction of the first base plates 38 and a
portion folded back therefrom that linearly extends from the other
side to the one side in the width direction of the first base
plates 38 are repeatedly provided between the first inflow port 50
and the first feed-out port 52.
[0037] In one of plate surfaces in a thickness direction of each of
the second base plates 40 (see FIG. 6), a plurality of second flow
passage groove portions 54 for forming the plurality of second flow
passages 34 are formed. Note that, similarly to FIG. 5, FIG. 6
illustrates an external shape of the entirety of each of the
plurality of second flow passage groove portions 54 formed in each
of the second base plates 40. In other words, in FIG. 6,
illustration of each of the second flow passage groove portions 54
is omitted, but, in practice, the plurality of second flow passage
groove portions 54 are arranged parallel to each other in the
external shape as illustrated in FIG. 6. Openings of the plurality
of second flow passage groove portions 54 formed in the one of the
plate surfaces of each of the second base plates 40 are sealed by
one of the first base plates 38 that is stacked on this plate
surface. The plurality of second flow passage groove portions 54 in
which these openings are sealed form the plurality of second flow
passages 34 that are arranged on one of plate surface sides of each
of the second base plates 40 while lying along this one of the
plate surfaces.
[0038] The plurality of second flow passages 34 formed in each of
the second base plates 40 are separated into two lines.
Specifically, these plurality of second flow passages 34 are made
of the second flow passages 34 of one group that are arranged, in
view of the center in a width direction of the second base plates
40, on one side in the width direction thereof and the second flow
passages 34 of the other group that are arranged, in view of the
center in the width direction of the second base plates 40, on the
other side in the width direction thereof. Each of the second flow
passages 34 of the one group has a meandering shape in which a
portion that linearly extends from a center side in the width
direction of the second base plates 40 to an edge side on the one
side in the width direction of the second base plates 40 and a
portion folded back therefrom that linearly extends to the center
side in the width direction of the second base plates 40 are
repeatedly provided. Moreover, each of the second flow passages 34
of the other group has such a meandering shape as to be symmetrical
to the second flow passages 34 of the one group with respect to the
center in the width direction of the second base plates 40.
[0039] One end of each of the second flow passages 34 that are
formed in the second base plates 40 opens at an end surface on one
side in a longitudinal direction of the stacked body 26 that lies
along a longitudinal direction of the second base plates 40,
specifically at the end surface on a side on which the first
feed-out port 52 is disposed. An opening of each of these second
flow passages 34 at the one end is a second inflow port 34a that
receives the brine. The second inflow port 34a is an example of an
inflow port of each of the second flow passages of the present
invention. An end portion of each of the second flow passages 34 at
a side opposite to the second inflow port 34a that are formed in
the second base plates 40 opens at an end surface on the other side
in the longitudinal direction of the stacked body 26 that lies
along the longitudinal direction of the second base plates 40,
specifically at the end surface on a side on which the first inflow
port 50 is disposed. An opening of each of these second flow
passages 34 at the opposite side is a second feed-out port 34b that
discharges the brine that has flown through each of the second flow
passages 34. The second feed-out port 34b is an example of a
feed-out port of each of the second flow passages of the present
invention.
[0040] In the stacked body 26 configured as described above, a
formation region of portions of the plurality of first flow
passages 32 arranged on one of the plate surface sides of the first
base plates 38 that linearly extend in the width direction of the
first base plates 38 and a formation region of portions of the
plurality of second flow passages 34 arranged on one of the plate
surface sides of the second base plates 40 that linearly extend in
the width direction of the second base plates 40 corresponds to
each other in such a manner as to overlap with each other in view
of the stacking direction of the base plates 38, 40. Moreover, the
heat exchanger 10 (stacked body 26) is configured such that the
first inflow port 50 and the second feed-out ports 34b are
positioned upward while the first feed-out port 52 and the second
inflow ports 34a are positioned downward, and the longitudinal
direction of the stacked body 26 (longitudinal direction of each of
the base plates 38, 40) corresponds to an upward/downward
direction. In other words, in the stacked body 26 of the heat
exchanger 10, the first inflow port 50 and the first feed-out port
52 of each of the first flow passages 32 are disposed such that the
hydrogen gas that is fed from the first inflow port 50 into each of
the first flow passages 32 and flows through each of the first flow
passages 32 toward the first feed-out port 52 generally moves from
upward to downward in a vertical direction orthogonal to the
stacking direction of the first base plates 38 and the second base
plates 40. Meanwhile, the second inflow ports 34a and the second
feed-out ports 34b of the corresponding second flow passages 34 are
disposed such that the brine that is fed from the second inflow
ports 34a into the corresponding second flow passages 34 and flows
through the corresponding second flow passages 34 toward the second
feed-out ports 34b generally moves from downward to upward in the
vertical direction.
[0041] The supply header 28 is attached to the end surface of the
stacked body 26 in which the second inflow ports 34a are formed.
The pipe 20 (see FIG. 1) is connected to the supply header 28. The
brine that has been delivered from the first pump 6 is supplied
through the pipe 20 to the supply header 28. An interior space
through which the supplied brine passes is provided in the supply
header 28. This interior space communicates with all the second
inflow ports 34a of the second flow passages 34 provided in the
stacked body 26 while the supply header 28 is attached to the
stacked body 26. In other words, the brine that has been supplied
to the supply header 28 is distributed from the interior space of
the supply header 28 to the second inflow ports. 34a of the
corresponding second flow passages 34 and fed thereinto.
[0042] The discharge header 30 is attached to the end surface of
the stacked body 26 in which the second feed-out ports 34b are
formed. The pipe 22 (see FIG. 1) is connected to the discharge
header 30. An interior space is provided in the discharge header
30. This interior space communicates with all the second feed-out
ports 34b of the second flow passages 34 provided in the stacked
body 26 while the discharge header 30 is attached to the stacked
body 26. The brine that has flown through each of the second flow
passages 34 flows out from the second feed-out ports 34b of the
corresponding second flow passages 34 into the interior space of
the discharge header 30, and is discharged from the interior space
to the pipe 22.
[0043] Moreover, the heat exchanger 10 of the cooling system
according to this embodiment has a configuration, such as a shape,
a size, and the number of the flow passages 32, 34, and the number
of stacked layers of the base plates 38, 40 forming the stacked
body 26, that is designed in such a manner as to satisfy a
relationship of Formula (1) below. In Formula (1) below, an amount
of heat exchange required for the heat exchanger 10 is Q (kW), an
overall heat transfer coefficient that is a value relative to the
configuration of the heat exchanger 10 is U (kW/m.sup.2.degree.
C.), a heat transfer area in the heat exchanger 10 is A (m.sup.2),
and a logarithmic mean temperature determined based on the
temperature of the brine at the second inflow ports 34a of the
second flow passages 34 and the temperature of the brine at the
second feed-out ports 34b of the second flow passages 34 is dT
(.degree. C.).
Q=U.times.A.times.dT (1)
[0044] The second inflow port temperature detection portion 60 (see
FIGS. 1 and 2) is connected to the supply header 28. The second
inflow port temperature detection portion 60 is a detector for
detecting the temperature of the brine fed into the second inflow
ports 34a of the second flow passages 34. In other words, the
second inflow port temperature detection portion 60 detects the
temperature of the brine at the second inflow ports 34a.
[0045] The second feed-out port temperature detection portion 62
(see FIGS. 1 and 2) is connected to the discharge header 30. The
second feed-out port temperature detection portion 62 is a detector
for detecting the temperature of the brine discharged from the
second feed-out ports 34b of the second flow passages 34. In other
words, the second feed-out port temperature detection portion 62
detects the temperature of the brine at the second feed-out ports
34b.
[0046] The first feed-out port temperature detection portion 64
(see FIGS. 1 and 2) is connected to the first feed-out port 52 of
the first flow passages 32. The first feed-out port temperature
detection portion 64 is a detector for detecting a temperature of
the hydrogen gas discharged from the first feed-out port 52. In
other words, the first feed-out port temperature detection portion
64 detects the temperature of the hydrogen gas at the first
feed-out port 52.
[0047] The second inflow port temperature detection portion 60, the
second feed-out port temperature detection portion 62, and the
first feed-out port temperature detection portion 64 transmit data
of detected temperatures to the control unit 58 respectively. The
control unit 58 controls the temperature of the brine flowing
through each of the second flow passages 34. Based on the received
data of each of the detected temperatures, the control unit 58
controls an operation of the cooler 2 while controlling the flow
rate of the brine delivered from the first pump 6, thereby
controlling the temperature of the brine flowing through each of
the second flow passages 34. The control unit 58 controls the
operation of the cooler 2 while controlling the flow rate of the
brine delivered from the first pump 6 such that the temperature of
the brine at the second feed-out ports 34b is higher than the
temperature of the hydrogen gas at the first feed-out port 52.
[0048] Next, the hydrogen gas cooling method according to this
embodiment will be described.
[0049] In the hydrogen gas cooling method according to this
embodiment, the cooling system as described above is prepared.
Then, the cooler 2 (see FIG. 1) allows the brine to be subjected to
heat exchange with a low-temperature refrigerant, thereby cooling
the brine. The cooled brine is delivered from the discharge portion
2b through the pipe 18 to the first reservoir chamber 12 of the
tank 4. The brine that has been fed into the first reservoir
chamber 12 is temporarily stored in the first reservoir chamber 12
while discharged to the pipe 20 due to a suction force of the first
pump 6. The brine that has been discharged to the pipe 20 is
delivered by the first pump 6 to the heat exchanger 10, and fed
through the interior space of the supply header 28 (see FIGS. 2 and
3) into each of the second flow passages 34 in the stacked body 26
(see FIG. 6) from the second inflow ports 34a thereof.
[0050] Based on data of the detected temperature received from the
second inflow port temperature detection portion 60, the control
unit 58 controls the operation (cooling force) of the cooler 2 for
cooling the brine such that the temperature of the brine at the
second inflow ports 34a is -40.degree. C. Specifically, the control
unit 58 allows the cooler 2 to adjust the temperature of the
refrigerant such that the detected temperature of the second inflow
port temperature detection portion 60 is -40.degree. C., thereby
controlling the cooling force of this cooler 2. In detail, when the
detected temperature of the second inflow port temperature
detection portion 60 is above -40.degree. C., the control unit 58
transmits to the cooler 2 the control signal indicating an increase
of the cooling power, and the cooler 2 that has received this
control signal increases the cooling power in accordance with this
control signal. Consequently, the temperature of the brine at the
second inflow ports 34a that is detected by the second inflow port
temperature detection portion 60 decreases close to -40.degree. C.
On the other hand, when the detected temperature of the second
inflow port temperature detection portion 60 is below -40.degree.
C., the control unit 58 transmits to the cooler 2 the control
signal indicating a decrease of the cooling power, and the cooler 2
that has received this control signal decreases the cooling power
in accordance with this control signal. Consequently, the
temperature of the brine at the second inflow ports 34a that is
detected by the second inflow port temperature detection portion 60
increases close to -40.degree. C.
[0051] The brine that has been fed into each of the second flow
passages 34 flows from the second inflow ports 34a toward the
second feed-out ports 34b through these second flow passages 34.
The brine that flows through each of these second flow passages 34
generally moves from downward to upward in the vertical direction
orthogonal to the stacking direction of the base plates 38, 40 of
the stacked body 26.
[0052] Meanwhile, the compressor 100 (see FIG. 1) compresses the
hydrogen gas. The compressed high-pressure hydrogen gas is fed from
the compressor 100 into the first inflow port 50 of the heat
exchanger 10. The hydrogen gas fed into this first inflow port 50
is compressed in the compressor 100 and then cooled by cooling
water to have a temperature of 40.degree. C. Then, the hydrogen gas
that has been fed into the first inflow port 50 is distributed to
each of the first flow passages 32 in the stacked body 26 (see FIG.
5) to be supplied. The hydrogen gas that has been supplied to each
of the first flow passages 32 flows through these first flow
passages 32 from a side of the first inflow port 50 toward the
first feed-out port 52, and generally moves from upward to downward
in the vertical direction. In this process, heat exchange between
the hydrogen gas flowing through each of the first flow passages 32
(see FIG. 4) and the brine flowing through the second flow passages
34 adjacent to these first flow passages 32 (see FIG. 4) is
performed through a portion of the stacked body 26 that is
positioned between both these flow passages 32, 34. Thereby, the
hydrogen gas is cooled. Meanwhile, the temperature of the hydrogen
gas gradually decreases as the hydrogen gas flows toward downstream
of each of the first flow passages 32 (toward the first feed-out
port 52). Consequently, the temperature of the hydrogen gas at the
first feed-out port 52 comes to -37.degree. C.
[0053] On the other hand, the temperature of the brine gradually
increases as the brine flows toward downstream of each of the
second flow passages 34 (toward the second feed-out ports 34b). The
rate of the temperature increase of the brine at this time differs
depending on the temperature and the flow rate of the brine fed
into the second flow passages 34. In this embodiment, the control
unit 58 controls the flow rate of delivering the brine fed into
each of the second flow passages 34, namely the flow rate in which
the first pump 6 delivers the brine such that the temperature of
the brine at the second feed-out ports 34b is higher than the
temperature of the hydrogen gas at the first feed-out port 52
(-37.degree. C.) while the temperature of the brine at the second
feed-out ports 34b is higher by at least 10.degree. C. than the
temperature of the brine at the second inflow ports 34a
(-40.degree. C.). Specifically, the control unit 58 controls the
flow rate of delivering the brine through the first pump 6 to such
a flow rate that the temperature of the brine at the second
feed-out ports 34b is -30.degree. C.
[0054] At this time, the control unit 58 controls the flow rate of
delivering the brine through the first pump 6 based on data of the
detected temperature received from. the first feed-out port
temperature detection portion 64, data of the detected temperature
received from the second inflow port temperature detection portion
60, and data of the detected temperature received from the second
feed-out port temperature detection portion 62.
[0055] Specifically, when the detected temperature of the first
feed-out port temperature detection portion 64 and the detected
temperature of the second feed-out port temperature detection
portion 62 are compared with each other, and the detected
temperature of the second feed-out port temperature detection
portion 62 is lower than or equal to the detected temperature of
the first feed-out port temperature detection portion 64, the
control unit 58 allows the first pump 6 to decrease the flow rate
of delivering the brine until the detected temperature of the
second feed-out port temperature detection portion 62 is higher
than the detected temperature of the first feed-out port
temperature detection portion 64. At this time, the control unit 58
transmits to the first pump 6 the control signal indicating a
decrease of the delivery flow rate, and the first pump 6 decreases
the flow rate of delivering the brine in accordance with the
received control signal.
[0056] Meanwhile, when the detected temperature of the second
feed-out port temperature detection portion 62 is higher than the
detected temperature of the second inflow port temperature
detection portion 60, and a difference in temperature between the
detected temperature of the second feed-out port temperature
detection portion 62 and the detected temperature of the second
inflow port temperature detection portion 60 is less than
10.degree. C., the control unit 58 allows the first pump 6 to
decrease the flow rate of delivering the brine until this
difference in temperature is 10.degree. C. or more. Also at this
time, the control unit 58 transmits to the first pump 6 the control
signal indicating a decrease of the delivery flow rate, thereby
allowing the first pump 6 to decrease the flow rate of delivering
the brine.
[0057] Meanwhile, at this time, the control unit 58 controls the
flow rate of delivering the brine through the first pump 6 such
that the detected temperature of the second feed-out port
temperature detection portion 62 is -30.degree. C. In other words,
when the detected temperature of the second feed-out port
temperature detection portion 62 is below -30.degree. C., the
control unit 58 transmits to the first pump 6 the control signal
indicating a decrease of the delivery flow rate, and the first pump
6 decreases the flow rate of delivering the brine in accordance
with the received control signal. Meanwhile, when the detected
temperature of the second feed-out port temperature detection
portion 62 is above -30.degree. C., the control unit 58 transmits
to the first pump 6 the control signal indicating an increase of
the delivery flow rate, and the first pump 6 increases the flow
rate of delivering the brine in accordance with the received
control signal.
[0058] The hydrogen gas that has been cooled is discharged through
the first feed-out port 52 of each of the first flow passages 32
(see FIGS. 2 and 5) and supplied to the fuel cell vehicle 90 (see
FIG. 1). On the other hand, the brine that has been subjected to
heat exchange is discharged from the second feed-out ports 34b of
the corresponding second flow passages 34 through the interior
space of the discharge header 30 to the pipe 22 (see FIG. 1) while
fed through this pipe 22 into the second reservoir chamber 14 of
the tank 4 and stored. The brine that has been subjected to heat
exchange and is stored in the second reservoir chamber 14 is sucked
by the second pump 8 through the pipe 24 while delivered to the
cooler 2, and fed from the feeding portion 2a thereof into the
cooler 2. The brine that has been subjected to heat exchange and is
fed into the cooler 2 is cooled again and supplied from the cooler
2 to the heat exchanger 10.
[0059] In the manner as described above, the hydrogen gas cooling
method according to this embodiment is performed.
[0060] In this embodiment, the hydrogen gas is cooled through heat
exchange in the stacked body 26 of the heat exchanger 10 between
the hydrogen gas flowing through each of the first flow passages 32
that are microchannels and the brine flowing through each of the
second flow passages 34 that are microchannels. Accordingly, a heat
transfer efficiency of the hydrogen gas per unit volume of the
brine is enhanced so that a hydrogen gas cooling efficiency can be
enhanced.
[0061] Moreover, the temperature of the hydrogen gas flowing
through the first flow passages 32 decreases as the hydrogen gas
flows downstream, and the temperature of the brine flowing through
the second flow passages 34 increases as the brine flows
downstream, namely toward the first inflow port 50 of the first
flow passages 32. In this embodiment, the hydrogen gas flowing
through each of the first flow passages 32 generally moves from
upward to downward while the brine flowing through each of the
second flow passages 34 generally moves from downward to upward so
that, as the hydrogen gas flows downstream of the first flow
passages 32, the hydrogen gas is allowed to be subjected to heat
exchange with the further low-temperature brine upstream of the
second flow passages 34. Thus, the hydrogen gas cooling efficiency
can be further enhanced.
[0062] Further, in this embodiment, the temperature and the flow
rate of the brine fed into each of the second flow passages 34 are
controlled such that the temperature of the brine at the second
feed-out ports 34b of the second flow passages 34 is higher than
the temperature of the hydrogen gas at the first feed-out port 52
of the first flow passages 32. Accordingly, compared with a case in
which the temperature of the brine at the second feed-out ports 34b
of the second flow passages 34 is lower than or equal to the
temperature of the hydrogen gas at the first feed-out port 52 of
the first flow passages 32, cold heat per brine flow rate (unit
volume) that is provided from the brine to the hydrogen gas in the
heat exchanger 10 is greater so that the hydrogen gas can be
further effectively cooled.
[0063] As described above, in this embodiment, the hydrogen gas
cooling efficiency can be enhanced so that, even if an amount of
use of the brine is reduced, or if the brine is not excessively
cooled to a low temperature, the hydrogen gas can be sufficiently
cooled.
[0064] Moreover, in this embodiment, the multitude of first flow
passages 32 that are microchannels and the multitude of second flow
passages 34 that are microchannels can be accumulated in the
stacked body 26 of the heat exchanger 10. Accordingly, the heat
exchanger 10 is designed to be downsized while an amount of
hydrogen gas cooling treatment can be sufficiently ensured.
[0065] Thus, in this embodiment, an amount of use of the brine that
is used for cooling the hydrogen gas is reduced, an increase of an
energy required for cooling the brine in the cooler 2 (energy
required for cooling the refrigerant) can be suppressed and the
hydrogen gas can be sufficiently cooled, while the heat exchanger
10 is downsized and, at the same time, an amount of hydrogen gas
cooling treatment is ensured. Moreover, in this embodiment, an
amount of use of the brine can be reduced, whereby an energy
required for driving the first pump 6 and the second pump 8 for
circulating the brine between the cooler 2 and the heat exchanger
10 can be reduced.
[0066] Moreover, in this embodiment, each of the first flow
passages 32 and each of the second flow passages 34 are formed to
have a meandering shape. Accordingly, compared with a case in
which, for example, these flow passages are formed to have a linear
shape, the number of the flow passages 32, 34 provided per sheet of
each of the base plates 38, 40 becomes small, but the length of
each of the flow passages 32, 34 can be lengthened. Consequently, a
heat transfer area of the first flow passages 32 and the second
flow passages 34 in the stacked body 26 can be sufficiently
ensured. Moreover, the number of the flow passages 32, 34 provided
per sheet of each of the base plates 38, 40 becomes small, whereby,
even when total flow rates of fluids allowed to flow through these
flow passages 32, 34 are the same, the velocity of flow of the
fluids flowing through each of the flow passages 32, 34,
respectively, can be increased. Generally, if the velocity of flow
of a fluid flowing through a flow passage increases, the turbulence
of the fluid in the flow passage increases and consequently a heat
transfer performance improves. Accordingly, in this embodiment,
while the heat transfer area of the first flow passages 32 and the
second flow passages 34 can be sufficiently ensured, increasing the
velocity of flow of the hydrogen gas flowing through each of the
first flow passages 32 and the velocity of flow of the brine
flowing through each of the second flow passages 34 allows the heat
transfer performance between these hydrogen gas and brine to
improve. Thus, the hydrogen gas can be further effectively
cooled.
[0067] Moreover, in this embodiment, the flow rate of the brine fed
into each of the second flow passages 34 is controlled such that
the temperature of the brine at the second feed-out ports 34b of
the second flow passages 34 is higher by at least 10.degree. C.
than the temperature of the brine at the second inflow ports 34a of
the second flow passages 34. Accordingly, the cold heat that is
provided from the brine flowing through the second flow passages 34
to the hydrogen gas flowing through the first flow passages 32 in
the heat exchanger 10 can be sufficiently magnified. Consequently,
the hydrogen gas cooling efficiency can be further enhanced.
[0068] Moreover, in this embodiment, the temperature of the brine
fed into each of the second flow passages 34 is controlled such
that the temperature of the brine at the second inflow ports 34a of
the second flow passages 34 is -40.degree. C. Accordingly, while
hydrogen embrittlement of the stacked body 26 of the heat exchanger
10 is suppressed, the hydrogen gas can be sufficiently cooled.
Specifically, it is known that if stainless steel that is a
material of each of the base plates 38, 40 forming the stacked body
26 is in contact with a hydrogen gas while cooled to a low
temperature below -40.degree. C., hydrogen embrittlement becomes
remarkable. Thus, as in this embodiment, the temperature of the
brine fed into each of the second flow passages 34 is controlled
such that the temperature of the brine at the second inflow ports
34a is -40.degree. C., whereby the temperature of the stacked body
26 is -40.degree. C. or more and hydrogen embrittlement can be
suppressed. Moreover, the brine of -40.degree. C. is fed into the
second inflow ports 34a, whereby hydrogen embrittlement of the
stacked body 26 can be suppressed while the hydrogen gas flowing
through the first flow passages 32 can be sufficiently cooled.
[0069] Note that it should be understood that the embodiment
disclosed herein is exemplary and not restrictive in all aspects.
The scope of the present invention is defined not by the
description of the above embodiment but by the claims, and includes
equivalents of the claims and all modifications within the scope of
the claims.
[0070] For example, as shapes of the first flow passages and the
second flow passages, various shapes other than the above-described
shape can be applied. For example, the first flow passages and the
second flow passages are not limited to passages having a
meandering shape in which folding backs are repeated as described
above, but may be passages that linearly extend.
[0071] Moreover, the number of the first flow passages formed per
first base plate and the number of the second flow passages formed
per second base plate may be optionally determined. Moreover, the
width and the cross-sectional shape of each of the first flow
passages and the width and the cross-sectional shape of each of the
second flow passages may be optionally determined.
[0072] Moreover, in the embodiment as described above, the first
base plates in which the first flow passages are arranged and the
second base plates in which the second flow passages are arranged
are alternately stacked upon one another, to which the
configuration of stacking layers is not limited. For example, two
or more sheets of the second base plates in which the second flow
passages that allow the brine to flow therethrough may be stacked
upon one sheet of the first base plates in which the first flow
passages that allow the hydrogen gas to flow therethrough.
[0073] Moreover, directions of the arrangement of the heat
exchanger (stacked body) are not limited to the direction in which
the longitudinal direction of the base plates corresponds to the
upward/downward direction as described above. For example, the heat
exchanger (stacked body) may be arranged in a direction in which
the longitudinal direction of the base plates corresponds to the
horizontal direction, otherwise in a slanted direction.
Outline of Embodiment
[0074] The embodiment as described above is summarized as
below.
[0075] The hydrogen gas cooling method according to the
above-described embodiment is a hydrogen gas cooling method using a
brine that is a non-evaporative antifreeze, the method including: a
preparation step of preparing a heat exchanger including a stacked
body in which a first layer in which a plurality of first flow
passages that are fine flow passages are arranged and a second
layer in which a plurality of second flow passages that are fine
flow passages are arranged are stacked upon one another; and a
cooling step in which a hydrogen gas is allowed to flow through
each of the first flow passages while a brine having a temperature
lower than the hydrogen gas is allowed to flow through each of the
second flow passages to perform heat exchange between the hydrogen
gas flowing through the first flow passages and the brine flowing
through the second flow passages, thereby cooling the hydrogen gas,
in which, in the cooling step, the hydrogen gas is allowed to flow
through each of the first flow passages such that the hydrogen gas
flowing through each of the first flow passages moves from one side
to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer while
the brine is allowed to flow through each of the second flow
passages such that the brine flowing through each of the second
flow passages moves from the other side to the one side in the
particular direction, and a temperature and a flow rate of the
brine fed into each of the second flow passages are controlled such
that the temperature of the brine at a feed-out port of the second
flow passages is higher than a temperature of the hydrogen gas at a
feed-out port of the first flow passages.
[0076] In this hydrogen gas cooling method, the hydrogen gas is
cooled through heat exchange in the stacked body of the heat
exchanger between the hydrogen gas flowing through each of the
first flow passages that are fine flow passages and the brine
flowing through each of the second flow passages that are fine flow
passages. Compared with conventional hydrogen gas cooling methods
using heat exchange through a heat transfer medium filled into the
filled bath and conventional hydrogen gas cooling methods using
heat exchange between a refrigerant and a hydrogen gas in a dual
pipe, a heat transfer efficiency of the hydrogen gas per unit
volume of the brine is enhanced. Consequently, a hydrogen gas
cooling efficiency per unit volume of the brine can be
enhanced.
[0077] Moreover, the temperature of the hydrogen gas flowing
through the first flow passages decreases as the hydrogen gas flows
downstream, and the temperature of the brine flowing through the
second flow passages increases as the brine flows downstream,
namely toward the hydrogen gas inflow port of the first flow
passages. In this hydrogen gas cooling method, the hydrogen gas is
fed into each of the first flow passages and the brine is fed into
each of the second flow passages such that the hydrogen gas flowing
through each of the first flow passages moves from one side to the
other side in a particular direction orthogonal to a stacking
direction of each of the layers of the stacked body while the brine
flowing through each of the second flow passages moves from the
other side to the one side. Accordingly, as the hydrogen gas flows
downstream through the first flow passages, the hydrogen gas is
allowed to be subjected to heat exchange with the further
low-temperature brine upstream of the second flow passages. Thus,
the hydrogen gas cooling efficiency can be further enhanced.
[0078] Further, in this hydrogen gas cooling method, the
temperature and the flow rate of the brine fed into each of the
second flow passages are controlled such that the temperature of
the brine at the feed-out port of the second flow passages is
higher than the temperature of the hydrogen gas at the feed-out
port of the first flow passages. Accordingly, compared with a case
in which the temperature of the brine at the feed-out port of the
second flow passages is lower than or equal to the temperature of
the hydrogen gas at the feed-out port of the first flow passages,
cold heat per brine flow rate (unit volume) that is provided from
the brine to the hydrogen gas is greater. Consequently, the
hydrogen gas can be further effectively cooled.
[0079] As described above, in this cooling method, the hydrogen gas
cooling efficiency can be enhanced so that, even if an amount of
use of the brine is reduced, or if the brine is not excessively
cooled to a low temperature, the hydrogen gas can be sufficiently
cooled.
[0080] Moreover, in this cooling method, the plurality of first
flow passages that are fine flow passages and the plurality of
second flow passages that are fine flow passages can be accumulated
in the stacked body of the heat exchanger. Accordingly, the heat
exchanger is designed to be downsized while an amount of hydrogen
gas cooling treatment can be sufficiently ensured. Thus, in this
cooling method, an amount of use of the brine that is used for
cooling the hydrogen gas is reduced, an increase of an energy
required for cooling the brine can be suppressed and the hydrogen
gas can be sufficiently cooled, while the heat exchanger is
downsized and, at the same time, an amount of hydrogen gas cooling
treatment is ensured.
[0081] In the hydrogen gas cooling method as described above,
preferably, in the preparation step of preparing, as the heat
exchanger, a heat exchanger including, as the stacked body, a
stacked body in an interior of which each of the first flow
passages and each of the second flow passages are formed to each
have a meandering shape, and in the cooling step, the hydrogen gas
is allowed to flow along the meandering shape of each of the first
flow passages through each of the first flow passages, and the
brine is allowed to flow along the meandering shape of each of the
second flow passages through each of the second flow passages.
[0082] According to this configuration, compared with a case in
which, for example, the flow passages are formed to have a linear
shape, the number of the flow passages provided per layer becomes
small, but the length of each of the flow passages can be
lengthened. Accordingly, a heat transfer area of the first flow
passages and the second flow passages in the stacked body can be
sufficiently ensured. Moreover, the number of the flow passages
provided per layer becomes small, whereby, even when total flow
rates of fluids allowed to flow through these flow passages are the
same, the velocity of flow of the fluids flowing through each of
the flow passages, respectively, can be increased. Generally, if
the velocity of flow of a fluid flowing through a flow passage
increases, the turbulence of the fluid in the flow passage
increases and consequently a heat transfer performance improves.
Thus, in this configuration, while the heat transfer area of the
first flow passages and the second flow passages can be
sufficiently ensured, increasing the velocity of flow of the
hydrogen gas flowing through each of the first flow passages and
the velocity of flow of the brine flowing through each of the
second flow passages allows the heat transfer performance between
these hydrogen gas and brine to improve, and the hydrogen gas can
be further effectively cooled.
[0083] In the hydrogen gas cooling method as described above,
preferably, in the cooling step, the flow rate of the brine fed
into each of the second flow passages is controlled such that the
temperature of the brine at the feed-out port of the second flow
passages is higher by at least 10.degree. C. than the temperature
of the brine at an inflow port of the second flow passages.
[0084] According to this configuration, a specific condition of the
feeding flow rate of the brine into each of the second flow
passages in which the cold heat that is provided from the brine
flowing through the second flow passages to the hydrogen gas
flowing through the first flow passages in the stacked body of the
heat exchanger can be sufficiently magnified can be set.
[0085] In the hydrogen gas cooling method as described above,
preferably, in the cooling step, the temperature of the brine fed
into each of the second flow passages is controlled such that the
temperature of the brine at the inflow port of the second flow
passages is -40.degree. C.
[0086] According to this configuration, a temperature condition of
the brine fed into each of the second flow passages in which while
hydrogen embrittlement of the stacked body of the heat exchanger is
suppressed, the hydrogen gas can be effectively cooled can be
set.
[0087] The hydrogen gas cooling system according to the embodiment
as described above is a hydrogen gas cooling system using a brine
that is a non-evaporative antifreeze, preferably, the system
including: a cooler that cools the brine; a heat exchanger that is
connected to the cooler such that the brine circulates between the
heat exchanger and the cooler, and allows a hydrogen gas to be
subjected to heat exchange with the brine supplied from the cooler,
thereby cooling the hydrogen gas; a pump that delivers the brine
that has been cooled by the cooler from the cooler to the heat
exchanger; and a control unit that controls a temperature of the
brine, in which the heat exchanger includes a stacked body in which
a first layer in which a plurality of first flow passages that are
fine flow passages into which the hydrogen gas is fed and flows
therethrough are arranged and a second layer in which a plurality
of second flow passages that are fine flow passages into which the
brine is fed and flows therethrough are arranged are stacked upon
one another, and allows heat exchange between the hydrogen gas
flowing through the first flow passages and the brine flowing
through the second flow passages to be performed, each of the first
flow passages includes a first inflow port that receives the
hydrogen gas and a first feed-out port that discharges the hydrogen
gas, and the first inflow port and the first feed-out port are
disposed such that the hydrogen gas that is fed from the first
inflow port into the first flow passages and flows through the
first flow passages toward the first feed-out port moves from one
side to the other side in a particular direction orthogonal to a
stacking direction of the first layer and the second layer, each of
the second flow passages includes a second inflow port that
receives the brine and a second feed-out port that discharges the
brine, and the second inflow port and the second feed-out port are
disposed such that the brine that is fed from the second inflow
port into the second flow passages and flows through the second
flow passages toward the second feed-out port moves from the other
side to the one side in the particular direction, and the control
unit controls an operation of the cooler and a flow rate of the
brine that the pump delivers, such that the temperature of the
brine at the second feed-out port is higher than a temperature of
the hydrogen gas at the first feed-out port.
[0088] In this hydrogen gas cooling system, similarly to the
hydrogen gas cooling method as described above, an amount of use of
the brine that is used for cooling the hydrogen gas is reduced, an
increase of an energy required for cooling the brine can be
suppressed and the hydrogen gas can be sufficiently cooled, while
the heat exchanger is downsized and, at the same time, an amount of
hydrogen gas cooling treatment is ensured.
[0089] Preferably, the hydrogen gas cooling system as described
above further includes: a first feed-out port temperature detection
portion that detects the temperature of the hydrogen gas at the
first feed-out port; and a second feed-out port temperature
detection portion that detects the temperature of the brine at the
second feed-out port, in which based on the temperature detected by
the first feed-out port temperature detection portion and the
temperature detected by the second feed-out port temperature
detection portion, the control unit controls the flow rate of the
brine that the pump delivers.
[0090] In the hydrogen gas cooling system as described above,
preferably, each of the first flow passages and each of the second
flow passages are formed in the stacked body to each have a
meandering shape.
[0091] According to this configuration, compared with a case in
which, for example, the flow passages are formed to have a linear
shape, the number of the flow passages provided per layer becomes
small, but the length of each of the flow passages can be
lengthened, and a heat transfer area of the first flow passages and
the second flow passages in the stacked body can be sufficiently
ensured. Moreover, the number of the flow passages provided per
layer becomes small, whereby, even when total flow rates of fluids
allowed to flow through these flow passages are the same, the
velocity of flow of the fluids flowing through each of the flow
passages, respectively, can be increased. Generally, if the
velocity of flow of a fluid flowing through a flow passage
increases, the turbulence of the fluid in the flow passage
increases and consequently a heat transfer performance improves.
Thus, in this configuration, while the heat transfer area of the
first flow passages and the second flow passages can be
sufficiently ensured, increasing the velocity of flow of the
hydrogen gas flowing through each of the first flow passages and
the velocity of flow of the brine flowing through each of the
second flow passages allows the heat transfer performance between
these hydrogen gas and brine to improve, and the hydrogen gas can
be further effectively cooled.
[0092] In the hydrogen gas cooling system as described above,
preferably, the control unit allows the pump to deliver the brine
such that the brine flows through each of the second flow passages
at such flow rate that the temperature of the brine at the second
feed-out port is higher by at least 10.degree. C. than the
temperature of the brine at the second inflow port.
[0093] According to this configuration, a flow rate of delivering
the brine through the pump in which the cold heat that is provided
from the brine flowing through the second flow passages to the
hydrogen gas flowing through the first flow passages in the stacked
body of the heat exchanger can be sufficiently magnified can be
specifically set.
[0094] In the hydrogen gas cooling system as described above,
preferably, the control unit controls a cooling force of the cooler
such that the temperature of the brine at the inflow port of the
second flow passages is -40.degree. C.
[0095] According to this configuration, a temperature of cooling
the brine through the cooler in which while hydrogen embrittlement
of the stacked body of the heat exchanger is suppressed, the
hydrogen gas can be effectively cooled can be specifically set.
[0096] As described above, according to the embodiment as described
above, an amount of use of the brine that is used for cooling the
hydrogen gas is reduced, an increase of an energy required for
cooling the brine can be suppressed and the hydrogen gas can be
sufficiently cooled, while the heat exchanger is downsized and, at
the same time, an amount of hydrogen gas cooling treatment is
ensured.
* * * * *