BACKGROUND OF THE INVENTION
(FIELD OF THE INVENTION)
[0001] The present invention relates to compression apparatuses for compressing a gas.
(DESCRIPTION OF THE RELATED ART)
[0002] In recent years, hydrogen stations for supplying hydrogen gas to fuel-cell vehicles
have been proposed. In hydrogen stations, a compression apparatus for supplying hydrogen
gas in a compressed state is used to efficiently charge fuel-cell vehicles with hydrogen
gas. The compression apparatus includes a compressor for compressing hydrogen gas,
and a gas cooler for cooling hydrogen gas that is raised in temperature by being compressed
by the compressor. For the gas cooler, use of a plate-type heat exchanger as described,
for example, in
JP 2000-283668 A has been proposed.
[0003] A plate-type heat exchanger includes a laminated body in which a large number of
plates are stacked in layers. Between the stacked plates, flow channels for circulating
fluids are individually formed. In the heat exchanger, heat exchange is performed
between fluids flowing through their respective flow channels that are adjacent to
each other in the plate stacking direction.
SUMMARY OF THE INVENTION
[0005] The above-described compression apparatus requires a large number of pipes to connect
the compressor and the gas cooler, and thus requires the securement of a large installation
space.
[0006] The present invention has been made to solve the above problem, and its object is
to reduce the size of compression apparatuses.
[0007] In order to achieve the above object, a compression apparatus according to the present
invention includes a compressor including a cylinder for compressing a gas, a heat
exchanger for cooling the gas compressed in the cylinder, and a circulation passage
for guiding the gas compressed in the cylinder into the heat exchanger, in which the
heat exchanger is solid-phase bonded to the cylinder, the circulation passage extends
through an area in which the heat exchanger and the cylinder face each other, and
the area is surrounded by a surface at which the heat exchanger and the cylinder are
solid-phase bonded.
[0008] In the present invention, the heat exchanger is solid-phase bonded to the cylinder.
The circulation passage extends through an area in which the heat exchanger and the
cylinder face each other, and the area is surrounded by a surface at which the heat
exchanger and the cylinder are solid-phase bonded. Therefore, installation space for
piping to connect the cylinder and the heat exchanger can be omitted, and the compression
apparatus can be reduced in size. Further, piping can be omitted, which also contributes
to a reduction in the number of components. Moreover, since the heat exchanger and
the cylinder are in close contact by solid-phase bonding, the possibility of gas leakage
can be reduced when a high-pressure gas discharged from the compressor flows through
the circulation passage.
[0009] Here, the solid-phase bonding may be diffusion bonding. In this aspect, leakage of
a high-pressure gas discharged from the compressor can be reduced more securely.
[0010] The circulation passage may extend through a flat surface at which the heat exchanger
and the cylinder are solid-phase bonded. In this aspect, one surface of the cylinder
facing the heat exchanger and one surface of the heat exchanger facing the cylinder
contact each other on the entire surfaces. These surfaces facing each other are solid-phase
bonded. This allows the surfaces to be bonded to be pressurized evenly during solid-phase
bonding. Thus, the possibility of gas leakage can be reduced more securely.
[0011] The heat exchanger may have a structure in which a plurality of plates are stacked
in layers so that cooling flow channels through which a cooling fluid for cooling
the gas flows and gas flow channels through which the gas flows are formed alternately.
In this case, a plate of the plurality of plates disposed at the end on the cylinder
side may be solid-phase bonded to the cylinder. In this aspect, good efficiency of
cooling the gas by the cooling fluid can be achieved. Further, the heat exchanger
can be easily mounted to the compressor.
[0012] In this aspect, the plates adjacent to each other may be solid-phase bonded. In this
aspect, since the adjacent plates are solid-phase bonded, the possibility of leakage
of a gas or a cooling fluid from between the plates can be reduced.
[0013] According to the present invention, compression apparatuses can be reduced in size.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
FIG. 1 is a schematic diagram illustrating a configuration of a compression apparatus
(with a recovery header removed) according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the compression apparatus taken in the position
of arrows II-II in FIG. 1.
FIG. 3 is a cross-sectional view of the compression apparatus taken in the position
of arrows III-III in FIG. 1.
FIG. 4 is a plan view of a hydrogen gas plate constituting a part of a gas cooler
provided in the compression apparatus.
FIG. 5 is a plan view of a cooling water plate constituting a part of the gas cooler.
FIG. 6 is a diagram corresponding to FIG. 1 in another embodiment of the present invention.
FIG. 7 is a diagram corresponding to FIG. 2 in another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Hereinafter, embodiments of the present invention will be described with reference
to the drawings.
[0016] A compression apparatus according to an embodiment of the present invention is a
compression apparatus used, for example, in a hydrogen station for supplying hydrogen
to fuel-cell vehicles.
[0017] As shown in FIGS. 1 to 3, the compression apparatus according to this embodiment
includes a compressor 2 for compressing hydrogen gas, and a gas cooler 4 for cooling
hydrogen gas after being compressed by the compressor 2. The gas cooler 4 is a microchannel
heat exchanger.
[0018] The compressor 2 is a reciprocating compressor, and includes a compression section
16 including a cylinder 5 and a piston 7, and a drive mechanism for driving the piston
7. The drive mechanism includes a crankcase 6, a crankshaft 8, a drive section not
shown, a cross guide 10, a crosshead 12, and a connecting rod 14.
[0019] In the crankcase 6, the crankshaft 8 is provided rotatably around a horizontal axis.
The drive section not shown is connected to the crankshaft 8, and transmits power
to the crankshaft 8 to rotate the crankshaft 8.
[0020] The cross guide 10 is a tubular member continuously provided to the crankcase 6.
In the cross guide 10, the crosshead 12 is housed reciprocatably in an axial direction
of the cross guide 10. The connecting rod 14 connects the crankshaft 8 and the crosshead
12, and converts the rotary motion of the crankshaft 8 into a linear reciprocating
motion for transmission to the crosshead 12.
[0021] The compression section 16 is constituted by a multistage compression mechanism,
and includes a first compression section 61 for performing first-stage compression
of hydrogen gas, and a second compression section 62 for performing second-stage compression
of hydrogen gas. The cylinder 5 has a first cylinder section 63 included in the first
compression section 61 and a second cylinder section 66 included in the second compression
section 62. The piston 7 has a first piston 64 included in the first compression section
61 and a second piston 67 included in the second compression section 62.
[0022] The first cylinder section 63 is formed in a tubular shape. One end of the first
cylinder section 63 is coupled to an axial end of the cross guide 10.
[0023] The interior space of the first cylinder section 63 functions as a first cylinder
chamber 63a. In the first cylinder chamber 63a, the first piston 64 is reciprocatably
housed. The first piston 64 is connected to the crosshead 12 by the piston rod 24.
Thus, the first piston 64 moves with the crosshead 12 in an integrated manner.
[0024] The second cylinder section 66 is formed integrally with the first cylinder section
63. The second cylinder section 66 is formed with a bottomed hole that communicates
with the first cylinder chamber 63a and extends in an axial direction of the second
cylinder section 66. An axial end of the hole is closed by an end wall 66c of the
second cylinder section 66. The hole functions as a second cylinder chamber 66a. The
second cylinder chamber 66a reciprocatably houses the second piston 67.
[0025] The first cylinder chamber 63a and the second cylinder chamber 66a are spaces both
in circular cross-sectional shapes. The second cylinder chamber 66a is smaller in
diameter than the first cylinder chamber 63a, and is formed coaxially with the first
cylinder chamber 63a. In the first cylinder chamber 63a, a space between the first
piston 64 and a partition wall 25 on the piston rod 24 side functions as a first compression
chamber 63b for compressing hydrogen gas.
[0026] The second piston 67 is connected to an end of the first piston 64 opposite to an
end to which the piston rod 24 is connected, and extends from the first piston 64
to the side opposite to the piston rod 24. The first piston 64 and the second piston
67 are formed both in cylindrical shapes. The second piston 67 is smaller in diameter
than the first piston 64.
[0027] In the second cylinder chamber 66a, a space between the second piston 67 and the
end wall 66c of the second cylinder section 66 functions as a second compression chamber
66b in which hydrogen gas compressed in the first compression chamber 63b is further
compressed. That is, a compression chamber 16a of the compression section 16 includes
the first compression chamber 63b and the second compression chamber 66b.
[0028] FIG. 2 is a cross-sectional view of the compression apparatus taken in the position
of arrows II-II in FIG. 1. The first cylinder section 63 includes a first inlet valve
chamber 69a, a first inlet side communication passage 70a, a first inlet passage 71,
a first delivery valve chamber 69b, a first delivery side communication passage 70b,
and a first delivery passage 72.
[0029] The first inlet valve chamber 69a and the first delivery valve chamber 69b are located
on the opposite sides of the first compression chamber 63b. The first inlet valve
chamber 69a and the first delivery valve chamber 69b individually extend in a direction
perpendicular to the moving direction of the first and second pistons 64 and 67 in
a horizontal plane.
[0030] In the first inlet valve chamber 69a, a first inlet valve 74a is housed and fixed
by a first inlet valve fixing flange 75a. The first inlet side communication passage
70a is a passage for connecting the first compression chamber 63b and the first inlet
valve chamber 69a. In the first delivery valve chamber 69b, a first delivery valve
74b is housed and fixed by a first delivery valve fixing flange 75b. The first delivery
side communication passage 70b is a passage for connecting the first compression chamber
63b and the first delivery valve chamber 69b.
[0031] The first inlet passage 71 is disposed on the upper side of the first inlet valve
chamber 69a, and extends downward from the upper surface of the first cylinder section
63 to be connected to the first inlet valve chamber 69a. To the upper end of the first
inlet passage 71, a supply pipe 76 is connected to supply hydrogen gas from a supply
source not shown therethrough.
[0032] The first delivery passage 72 extends from the first delivery valve chamber 69b to
the lower surface of the first cylinder section 63. The first delivery passage 72
has a first delivery passage opening 72a opening in the lower surface of the first
cylinder section 63.
[0033] FIG. 3 is a cross-sectional view of the compression apparatus taken in the position
of arrows III-III in FIG. 1. The lower surface of the second cylinder section 66 and
the lower surface of the first cylinder section 63 are formed flush in a planar shape.
That is, in the compressor 2, an area opposite to the gas cooler 4 is formed by a
flat surface.
[0034] The second cylinder section 66 includes a second inlet valve chamber 78a, a second
inlet side communication passage 79a, a second inlet passage 80, a second delivery
valve chamber 78b, a second delivery side communication passage 79b, and a second
delivery passage 81.
[0035] The second inlet valve chamber 78a and the second delivery valve chamber 78b are
located on the opposite sides of the second compression chamber 66b. The second inlet
valve chamber 78a and the second delivery valve chamber 78b individually extend in
a direction perpendicular to the moving direction in a horizontal plane. In the second
inlet valve chamber 78a, a second inlet valve 83a is housed and fixed by a second
inlet valve fixing flange 84a. The second inlet side communication passage 79a is
a passage for connecting the second compression chamber 66b and the second inlet valve
chamber 78a. In the second delivery valve chamber 78b, a second delivery valve 83b
is housed and fixed by a second delivery valve fixing flange 84b. The second delivery
side communication passage 79b is a passage for connecting the second compression
chamber 66b and the second delivery valve chamber 78b.
[0036] The second inlet passage 80 is disposed on the lower side of the second inlet valve
chamber 78a, and extends upward from the lower surface of the second cylinder section
66 to be connected to the second inlet valve chamber 78a. The second inlet passage
80 has a second inlet passage opening 80a opening in the lower surface of the second
cylinder section 66.
[0037] The second delivery passage 81 is disposed on the upper side of the second delivery
valve chamber 78b, and extends downward from the upper surface of the second cylinder
section 66. To the upper end of the second delivery passage 81, a communicating pipe
85 is connected.
[0038] The gas cooler 4 is a heat exchanger for cooling hydrogen gas compressed in the compressor
2 by water as a cooling fluid, and includes a main body 38, a supply header 42 (see
FIG. 3), and a recovery header 44 (see FIG. 3).
[0039] The main body 38 is a laminated body in which gas plates 46 and water plates 48 are
stacked in layers between a pair of end plates 50 and 50. In this embodiment, a partition
plate 88 is interposed in a middle position of the main body 38. The main body 38
is divided into two parts by the partition plate 88.
[0040] Specifically, the main body 38 includes a first cooling section 86 that is a heat
exchanger for cooling hydrogen gas after first-stage compression, and a second cooling
section 87 that is a heat exchanger for cooling hydrogen gas after second-stage compression.
The interior of the main body 38 is partitioned into the first cooling section 86
and the second cooling section 87 by the partition plate 88.
[0041] The first cooling section 86 is disposed on the compressor 2 side with respect to
the partition plate 88, and the second cooling section 87 is disposed opposite to
the compressor 2 with respect to the partition plate 88.
[0042] The first cooling section 86 and the second cooling section 87 each include the gas
plates 46 and the water plates 48. The gas plates 46 and the water plates 48 are disposed
alternately.
[0043] As shown in FIG. 4, each gas plate 46 is a rectangular plate formed from stainless
steel. Each gas plate 46 has an inflow passage through hole 46d and a discharge passage
through hole 46e. Further, a plurality of gas channel grooves 46a, a distribution
section groove 46b, and a recovery section groove 46c are formed in one surface of
each gas plate 46. The distribution section groove 46b is connected to the inflow
passage through hole 46d, and the recovery section groove 46c is connected to the
discharge passage through hole 46e. When the gas plates 46 and the water plates 48
are stacked on each other, gas flow channels 54 are formed by the gas channel grooves
46a and the water plates 48.
[0044] As shown in FIG. 5, like the gas plates 46, each water plate 48 is a rectangular
plate formed from stainless steel. Each water plate 48 has an inflow passage through
hole 48b and a discharge passage through hole 48c. A plurality of water channel grooves
48a is formed in one plate surface of each water plate 48. When the water plates 48
and the gas plates 46 are stacked on each other, cooling water flow channels 57 are
formed by the water channel grooves 48a and the gas plates 46.
[0045] The end plates 50 are each a rectangular plate formed from stainless steel. The end
plate 50 on the first cooling section 86 side is diffusion bonded to the lower surface
of the cylinder 5 (the first cylinder section 63 and the second cylinder section 66)
of the compressor 2, and is in close contact with the lower surface. Specifically,
being kept in close contact with each other, the cylinder 5 and the end plate 50 are
pressurized under a temperature condition lower than or equal to the melting points
of their base materials to an extent that it causes minimum plastic deformation, and
bonded utilizing the diffusion of atoms occurring between the bonded surfaces. The
upper surface of the end plate 50 is a flat surface and constitutes an area opposite
to the cylinder 5 of the compressor 2.
[0046] An inflow passage through hole 50b and a discharge passage through hole 50d are formed
in the end plate 50 (see FIGS. 2 and 3). Hydrogen gas discharged from the compressor
2 and introduced into the gas cooler 4 passes through the inflow passage through hole
50b. Hydrogen gas discharged from the gas cooler 4 passes through the discharge passage
through hole 50d.
[0047] The gas plates 46 in the first cooling section 86 are disposed opposite in orientation
to those in the second cooling section 87, and also the end plates 50a and the water
plates 48 are disposed opposite in orientation likewise. That is, the positional relationship
between the distribution section grooves 46b and the recovery section grooves 46c
of the gas plates 46 in the first cooling section 86 is opposite to that in the second
cooling section 87, and also the positional relationship between the inflow passage
through holes 46d and the discharge passage through holes 46e in the first cooling
section 86 is opposite to that in the second cooling section 87. For the end plates
50a and the water plates 48, the positional relationship between the inflow passage
through holes 48b and 50b and the discharge passage through holes 48c and 50d in the
first cooling section 86 is opposite to that in the second cooling section 87.
[0048] Adjacent plates of the gas plates 46, the water plates 48, the end plates 50, and
the partition plate 88 are bonded to each other by diffusion bonding.
[0049] In the first cooling section 86, the inflow passage through holes 46d, 48b, and 50b
of the respective plates communicate with each other, thereby forming a first gas
inflow passage 52a extending in the plate stacking direction. An opening 52c on the
inflow side of the first gas inflow passage 52a communicates with the first delivery
passage opening 72a of the first delivery passage 72. Thus, hydrogen gas compressed
in the first compression section 61 and flowing through the first delivery side communication
passage 70b and the first delivery passage 72 flows into the first gas inflow passage
52a. The hydrogen gas flowing through the first gas inflow passage 52a is introduced
into the gas flow channels 54 in the first cooling section 86. Accordingly, hydrogen
gas is allowed to flow from the compressor 2 into the gas cooler 4 without flowing
through any pipe.
[0050] In the first cooling section 86, the discharge passage through holes 46e, 48c, and
50d communicate with each other, thereby forming a first gas discharge passage 53a
extending in the plate stacking direction. An opening 53c on the discharge side of
the first gas discharge passage 53a communicates with the second inlet passage opening
80a of the second inlet passage 80. Thus, hydrogen gas cooled by cooling water in
the first cooling section 86 passes through the opening 53c of the first gas discharge
passage 53a. The hydrogen gas is discharged to the second compression section 62.
[0051] In the second cooling section 87, the inflow passage through holes 46d, 48b, and
50b of the respective plates communicate with each other, thereby forming a second
gas inflow passage 52b extending in the plate stacking direction. The second gas inflow
passage 52b guides hydrogen gas compressed in the second compression section 62 and
introduced into the second cooling section 87 through the communicating pipe 85 into
the gas flow channels 54 in the second cooling section 87.
[0052] In the second cooling section 87, the discharge passage through holes 46e, 48c, and
50d communicate with each other, thereby forming a second gas discharge passage 53b
extending in the plate stacking direction. The second gas discharge passage 53b discharges
hydrogen gas cooled by cooling water in the second cooling section 87 to a discharge
pipe 89.
[0053] As shown in FIG. 3, to one side of the right and left sides of the main body 38,
the supply header 42 to which a cooling water supply pipe 58 is connected is attached,
and to the other side, the recovery header 44 to which a cooling water recovery pipe
59 is connected is attached. In the gas cooler 4, cooling water flows from the cooling
water supply pipe 58 through the supply header 42, the cooling water channels 57 (see
FIG. 5), and the recovery header 44 to the cooling water recovery pipe 59.
[0054] When the compression apparatus is driven, hydrogen gas is taken in from the first
inlet passage 71 into the first compression chamber 63b via the first inlet valve
74a (see FIG. 2). In the first compression chamber 63b, the hydrogen gas is compressed
by the first piston 64 and discharged from the first cylinder section 63 through the
first delivery side communication passage 70b and the first delivery passage 72. The
hydrogen gas flows into the first cooling section 86 of the gas cooler 4 through the
first delivery passage opening 72a. That is, the first delivery side communication
passage 70b and the first delivery passage 72 function as a circulation passage 77
for guiding hydrogen gas compressed in the cylinder 5 to the heat exchanger.
[0055] In the first cooling section 86, the hydrogen gas flows from the first gas inflow
passage 52a into the gas flow channels 54 (FIG. 4), and is cooled by exchanging heat
with cooling water flowing through the cooling water flow channels 57 (FIG. 5). The
cooled hydrogen gas is discharged from the first cooling section 86 to the second
compression chamber 66b via the first gas discharge passage 53a. In the second compression
chamber 66b, the hydrogen gas is further compressed by the second piston 67.
[0056] The hydrogen gas compressed in the second compression chamber 66b is discharged through
the second delivery passage 81 to the communicating pipe 85. The hydrogen gas discharged
to the communicating pipe 85 flows into the second gas inflow passage 52b of the second
cooling section 87. After cooled in the second cooling section 87, the hydrogen gas
flows into the second gas discharge passage 53b and is discharged to the discharge
pipe 89.
[0057] In the compression apparatus according to this embodiment, since the gas cooler 4
is directly fixed to the compressor 2, piping between the compressor 2 and the gas
cooler 4 can be omitted. As a result, space for piping installation becomes unnecessary,
and thus the compression apparatus can be reduced in size. Further, the number of
pipes can be reduced, which also contributes to a reduction in the number of components.
Moreover, since the gas cooler 4 and the cylinder 5 are in close contact by diffusion
bonding, without the provision of a sealing member for sealing against hydrogen gas,
the possibility of gas leakage can be reduced when a high-pressure gas discharged
from the compressor 2 flows through the circulation passage.
[0058] In this embodiment, one surface of the cylinder 5 facing the gas cooler 4 (or the
first cooling section 86) and one surface of the gas cooler 4 (or the first cooling
section 86) facing the cylinder 5 contact each other on the entire surfaces. These
surfaces facing each other are diffusion bonded. This allows the surfaces to be bonded
to be pressurized evenly during diffusion bonding. Thus, the possibility of gas leakage
can be reduced more securely.
[0059] In this embodiment, since the gas cooler 4 consists of the plurality of plates 46
and 48 stacked in layers, good efficiency of cooling hydrogen gas by cooling water
can be achieved. Further, the gas cooler 4 can be easily mounted to the compressor
2.
[0060] In this embodiment, in the gas cooler 4, since the adjacent plates 46 and 48 are
diffusion bonded to each other, the possibility of leakage of hydrogen gas or cooling
water from between the plates 46 and 48 can be reduced.
[0061] It should be considered that the embodiment disclosed now is illustrative in all
respects and is not limiting. The scope of the present invention is indicated not
by the description of the above-described embodiment but by the scope of claims, and
also includes all modifications within a meaning and scope equivalent to the scope
of claims.
[0062] For example, as the gas cooler 4, other various plate-type heat exchangers such as
plate-fin type heat exchangers may be used. A plate-fin heat exchanger is different
from a microchannel heat exchanger in the manner in which a groove shape is machined
and the manner in which stacked layers are bonded to each other, but has a structure
functionally similar to that of the microchannel heat exchanger. A tube-type heat
exchanger may also be used as the heat exchanger.
[0063] In the above-described embodiment, the compressor 2 is configured to include the
compression section 16 composed of the plurality of compression sections 61 and 62,
which is not limiting. Alternatively, as shown in FIG. 6, for example, the compressor
2 may be configured to include a single-stage compression-type compression section
16, or may include a compression section with three or more stages (not shown). In
a compression apparatus including the single compression section 16 as shown in FIG.
6, the interior of a cylinder 5 is divided into two spaces by a piston 7. The space
opposite to a piston rod 24 functions as a compression chamber 16a. A delivery passage
18 communicating with the compression chamber 16a is provided at the cylinder 5. An
opening 18a of the delivery passage 18 is formed in the lower surface of the cylinder
5. The delivery passage 18 communicates with gas flow channels 54 of a gas cooler
4. The gas cooler 4 is not configured to be divided into a first cooling section 86
and a second cooling section 87, and thus a partition plate 88 is not provided. Thus,
hydrogen gas introduced from the delivery passage 18 into the gas flow channels 54
is cooled by cooling water in the gas flow channels 54, and then discharged from a
discharge pipe 89 of the gas cooler 4.
[0064] Further, application may be made to a compression apparatus in which a cross guide
10 and a cylinder 5 are coupled in a vertical direction so that the moving direction
of a piston 7 is a vertical direction, and a gas cooler 4 is mounted to a side of
the cylinder 5.
[0065] The gas flow channels 54 may alternatively be formed in a meandering shape on the
plate surface of each gas plate 46. The cooling water flow channels 57 may alternatively
be formed in a meandering shape on the plate surface of the each water plate 48. This
configuration can increase the surface areas of the gas flow channels 54 and the cooling
water flow channels 57, allowing for more effective cooling of hydrogen gas. The compression
apparatus in the above-described embodiments may be used for a gas lighter than air
such as helium gas or natural gas other than hydrogen gas, and may be used for compression
of a gas such as carbon dioxide.
[0066] In the above-described embodiments, the upper surface of the gas cooler 4 and the
lower surface of the cylinder 5 of the compressor 2 are individually formed flat,
and are configured to be solid-phase bonded over the entire surfaces. However, this
is not limiting. For example, as shown in FIG. 7, the lower surface of a cylinder
5 may be configured such that it partially has an area that is not flat, and at a
recessed area 5a, the lower surface of the cylinder 5 is not in close contact with
the upper surface of a gas cooler 4. That is, the cylinder 5 may be configured such
that an area in which a first delivery passage 72 opens and an area in which a gas
inflow passage 52a opens in the gas cooler 4 are not diffusion bonded. However, also
in this case, an area surrounding an opening 72a of the first delivery passage 72
needs to be diffusion bonded to the gas cooler 4 at the lower surface of the cylinder
5.
[0067] The above-described embodiments have a structure in which the gas cooler 4 and the
cylinder 5 are diffusion bonded, which is not limiting. For bonding between the gas
cooler 4 and the cylinder 5, another solid-phase bonding such as explosive welding
may be used.
[0068] A compression apparatus in the present invention includes a compressor including
a cylinder for compressing a gas, a gas cooler for cooling the gas compressed in the
cylinder, and a circulation passage for guiding the gas compressed in the cylinder
into the gas cooler. The gas cooler is diffusion bonded to the cylinder. In order
to reduce the size of the compression apparatus, the circulation passage extends through
an area in which the gas cooler and the cylinder face each other. At least areas surrounding
the area are diffusion bonded.