Gas booster

Abstract

A gas booster according to one embodiment includes a gas cylinder and a hydraulic cylinder. The gas cylinder includes a gas cylinder tube (31), a gas cover (32) for closing one opening of the gas cylinder tube (31), and a gas piston that is disposed within the gas cylinder tube (31) and forms a compression chamber (3a) between the gas cover (32) and the gas piston. The gas piston is connected by a rod to a hydraulic piston included in the hydraulic cylinder. The gas cover (32) has a gas intake flow path (61) and a gas discharge flow path that communicate with the compression chamber (3a), and a cooling flow path (81) through which a cooling medium flows.

Description

Gas Booster

[0001] The present disclosure relates to a gas booster for compressing gas.

[0002] Hydraulically driven gas boosters that compress gas have been known for some time. For example, Patent Document 1 discloses a gas booster 100 including a first structure 110 and a second structure 120 as shown in Fig. 6. The first structure 110 and the second structure 120 each include a gas cylinder 200 and a hydraulic cylinder 300 that are coaxially aligned.

[0003] Each gas cylinder 200 includes a gas cylinder tube 210 and a gas cover 220 that closes the opening of the gas cylinder tube 210 on the side opposite to the hydraulic cylinder 300. Furthermore, the gas cylinder 200 includes a gas piston 230 disposed within the gas cylinder tube 210. A compression chamber 240 is formed between the gas piston 230 and the gas cover 220. The gas cover 220 has a gas intake passage 221 and a gas discharge passage 222 that communicate with the compression chamber 240.

[0004] Each hydraulic cylinder 300 includes a hydraulic cylinder tube 310 and a pair of hydraulic covers 320, 330 that close openings on both sides of the hydraulic cylinder tube 310. Furthermore, the hydraulic cylinder 300 includes a hydraulic piston 340 disposed within the hydraulic cylinder tube 310. Drive chambers 350, 360 are formed between the hydraulic piston 340 and the hydraulic covers 320, 330. The hydraulic piston 340 is connected to the gas piston 230 by a rod 400 that passes through the hydraulic cover 330.

[0005] Special Publication No. 2021-522446

[0006] In the gas booster 100, the gas is compressed in the compression chamber 240 of each gas cylinder 200, causing the temperature of the gas to rise, thereby heating the entire gas cover 220. As a result, the temperatures of the gas flowing into the compression chamber 240 through the gas intake passage 221 and the gas flowing out of the compression chamber 240 through the gas discharge passage 222 rise. When the temperature of the gas flowing into the compression chamber 240 rises, the compression efficiency decreases, and the gas discharge amount of the gas booster 100 decreases. Furthermore, when the temperature of the gas flowing out of the compression chamber 240 rises, the strength of the gas piping connected to the gas discharge passage 222 may decrease.

[0007] Therefore, an object of the present disclosure is to provide a gas booster that can suppress a rise in temperature of gas flowing into a compression chamber and gas flowing out of a compression chamber.

[0008] The present disclosure provides a gas booster comprising: a gas cylinder including a gas cylinder tube, a gas cover closing one opening of the gas cylinder tube, and a gas piston disposed in the gas cylinder tube to form a compression chamber between itself and the gas cover; a hydraulic cylinder including a hydraulic cylinder tube, a pair of hydraulic covers closing openings on both sides of the hydraulic cylinder tube, and a hydraulic piston disposed in the hydraulic cylinder tube to form a pair of drive chambers between itself and the pair of hydraulic covers; and a rod connecting the hydraulic piston and the gas piston, wherein the gas cover has a gas intake flow path and a gas discharge flow path communicating with the compression chamber, and a cooling flow path through which a cooling medium flows.

[0009] According to the present disclosure, a gas booster is provided that can suppress a rise in temperature of gas flowing into a compression chamber and gas flowing out of a compression chamber.

[0010] Fig. 1 is a schematic diagram of a gas booster according to one embodiment; Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1; Fig. 3 is a plan cross-sectional view of a gas cover of a first gas cylinder taken along line III-III in Fig. 2; Fig. 4 is a plan cross-sectional view of a gas cover of a second gas cylinder; Fig. 5 is a plan cross-sectional view of a gas cover of a modified example; Fig. 6 is a schematic diagram of a conventional gas booster;

[0011] 1 shows a gas booster 1 according to one embodiment. In this embodiment, the gas booster 1 is a twin-shaft type, and compresses gas in two stages. The gas to be compressed is not particularly limited, but may be hydrogen, for example.

[0012] Specifically, the gas booster 1 includes a first structure 2A and a second structure 2B. The first structure 2A includes a first gas cylinder 3A, a first hydraulic cylinder 4A, and a rod 51, and the second structure 2B includes a second gas cylinder 3B, a second hydraulic cylinder 4B, and a rod 52.

[0013] The first structure 2A and the second structure 2B differ significantly in the size of the first gas cylinder 3A and the second gas cylinder 3B. Specifically, the diameter of a gas piston 37 (described later) of the second gas cylinder 3B is smaller than the diameter of a gas piston 33 (described later) of the first gas cylinder 3A. For example, the area of ​​the gas piston 33 is between two and ten times the area of ​​the gas piston 37.

[0014] In the first structure 2A, the first gas cylinder 3A and the first hydraulic cylinder 4A are aligned coaxially, and in the second structure 2B, the second gas cylinder 3B and the second hydraulic cylinder 4B are aligned coaxially. In this embodiment, the axial directions of the first gas cylinder 3A and the first hydraulic cylinder 4A and the second gas cylinder 3B and the second hydraulic cylinder 4B are vertical. Also, in this embodiment, the first hydraulic cylinder 4A is disposed below the first gas cylinder 3A, and the second hydraulic cylinder 4B is disposed below the second gas cylinder 3B. However, the axial directions of the first gas cylinder 3A and the first hydraulic cylinder 4A and the second gas cylinder 3B and the second hydraulic cylinder 4B may be horizontal.

[0015] With respect to the first structure 2A, the first gas cylinder 3A includes a gas cylinder tube 31, a gas cover 32, and a gas piston 33. The gas cylinder tube 31 is cylindrical and extends vertically, and the gas cover 32 closes the upper opening of the gas cylinder tube 31, which is the side opposite the first hydraulic cylinder 4A. The gas piston 33 is disposed within the gas cylinder tube 31 and forms a compression chamber 3a between itself and the gas cover 32.

[0016] The first gas cylinder 3A also includes a cylindrical jacket 34 that houses the gas cylinder tube 31 and extends from the gas cover 32 to a hydraulic cover 42 (described later). An annular cooling chamber is formed between the gas cylinder tube 31 and the jacket 34, and a coolant is supplied to and discharged from the cooling chamber. However, the jacket 34 may be omitted.

[0017] The gas cover 32 is, for example, disk-shaped. In this embodiment, the peripheral portion of the lower surface of the gas cover 32 is cut out to form a step portion 32a, and the upper end portion of the gas cylinder tube 31 engages with the step portion 32a. In other words, the gas cover 32 is partially fitted into the gas cylinder tube 31.

[0018] In this embodiment, the gas cover 32 has a gas suction port 6a and a gas discharge port 6b on its end surface facing radially outward. However, one or both of the gas suction port 6a and the gas discharge port 6b may be located on the upper surface of the gas cover 32. The gas cover 32 is formed with a gas suction passage 61 that runs from the gas suction port 6a to the compression chamber 3a, and a gas discharge passage 62 that runs from the compression chamber 3a to the gas discharge port 6b. In other words, the gas suction passage 61 and the gas discharge passage 62 communicate with the compression chamber 3a.

[0019] The first hydraulic cylinder 4A includes a hydraulic cylinder tube 41, a pair of hydraulic covers 42, 43, and a hydraulic piston 44. The hydraulic cylinder tube 41 is cylindrical and extends vertically, with the hydraulic cover 42 closing the upper opening of the hydraulic cylinder tube 41 and the hydraulic cover 43 closing the lower opening of the hydraulic cylinder tube 41. The hydraulic piston 44 is disposed within the hydraulic cylinder tube 41 and forms a first drive chamber 4a with the upper hydraulic cover 42, and a second drive chamber 4b with the lower hydraulic cover 43.

[0020] In this embodiment, the lower opening of the gas cylinder tube 31 is closed by the hydraulic cover 42. The rod 51 traverses the first drive chamber 4a and passes through the hydraulic cover 42 to connect the hydraulic piston 44 and the gas piston 33. However, similar to the gas booster 100 shown in Figure 6, the lower opening of the gas cylinder tube 31 may be closed by an intermediate cover, and an intermediate tube may be provided between the intermediate cover and the hydraulic cover 42 to surround the space around the rod 51.

[0021] The hydraulic covers 42, 43 are, for example, disk-shaped. In this embodiment, the hydraulic cover 42 has a supply / discharge port 7a on its end surface facing radially outward, and the hydraulic cover 43 has a supply / discharge port 7b on its end surface facing radially outward. However, the positions of the supply / discharge ports 7a, 7b are not limited to this. For example, the supply / discharge port 7a may be provided in the upper part of the hydraulic cylinder tube 41, thereby omitting a hydraulic flow path 71 (described later), or the supply / discharge port 7b may be provided in the lower part of the hydraulic cylinder tube 41, thereby omitting a hydraulic flow path 72 (described later).

[0022] The hydraulic cover 42 has a hydraulic flow path 71 formed from the supply / discharge port 7a to the first drive chamber 4a, and the hydraulic cover 43 has a hydraulic flow path 72 formed from the supply / discharge port 7b to the second drive chamber 4b.

[0023] With respect to the second structure 2B, the second gas cylinder 3B includes a gas cylinder tube 35, a gas cover 36, and a gas piston 37. The gas cylinder tube 35 is cylindrical and extends vertically, and the gas cover 36 closes the upper opening of the gas cylinder tube 35, which is the opposite side to the second hydraulic cylinder 4B. The gas piston 37 is disposed within the gas cylinder tube 35 and forms a compression chamber 3b between itself and the gas cover 36.

[0024] The second gas cylinder 3B also includes a cylindrical jacket 38 that houses the gas cylinder tube 35 and extends from the gas cover 36 to a hydraulic cover 46 (described later). An annular cooling chamber is formed between the gas cylinder tube 35 and the jacket 38, and a coolant is supplied to and discharged from the cooling chamber. However, the jacket 38 may be omitted.

[0025] The gas cover 36 is, for example, disk-shaped. In this embodiment, the peripheral edge of the underside of the gas cover 36 is cut out to form a step 36a, and the upper end of the gas cylinder tube 35 engages with the step 36a. In other words, the gas cover 36 is partially fitted into the gas cylinder tube 35.

[0026] In this embodiment, the gas cover 36 has a gas suction port 6c and a gas discharge port 6d on its end surface facing radially outward. However, one or both of the gas suction port 6c and the gas discharge port 6d may be located on the upper surface of the gas cover 36. The gas cover 36 is formed with a gas suction passage 63 that runs from the gas suction port 6c to the compression chamber 3b, and a gas discharge passage 64 that runs from the compression chamber 3b to the gas discharge port 6d. In other words, the gas suction passage 63 and the gas discharge passage 64 communicate with the compression chamber 3b.

[0027] The second hydraulic cylinder 4B includes a hydraulic cylinder tube 45, a pair of hydraulic covers 46, 47, and a hydraulic piston 48. The hydraulic cylinder tube 45 is cylindrical and extends vertically, with the hydraulic cover 46 closing the upper opening of the hydraulic cylinder tube 45 and the hydraulic cover 47 closing the lower opening of the hydraulic cylinder tube 45. The hydraulic piston 48 is disposed within the hydraulic cylinder tube 45 and forms a first drive chamber 4c between itself and the upper hydraulic cover 46, and a second drive chamber 4d between itself and the lower hydraulic cover 47.

[0028] In this embodiment, the lower opening of the gas cylinder tube 35 is closed by the hydraulic cover 46. The rod 52 traverses the first drive chamber 4c and passes through the hydraulic cover 46 to connect the hydraulic piston 48 and the gas piston 37. However, similar to the gas booster 100 shown in Figure 6, the lower opening of the gas cylinder tube 35 may be closed by an intermediate cover, and an intermediate tube may be provided between the intermediate cover and the hydraulic cover 46 to surround the space around the rod 52.

[0029] The hydraulic covers 46, 47 are, for example, disk-shaped. In this embodiment, the hydraulic cover 46 has a supply / discharge port 7c on its end surface facing radially outward, and the hydraulic cover 47 has a supply / discharge port 7d on its end surface facing radially outward. However, the positions of the supply / discharge ports 7c, 7d are not limited to this. For example, the supply / discharge port 7c may be provided in the upper part of the hydraulic cylinder tube 45, thereby omitting a hydraulic flow path 73 (described later), or the supply / discharge port 7d may be provided in the lower part of the hydraulic cylinder tube 45, thereby omitting a hydraulic flow path 74 (described later).

[0030] The hydraulic cover 46 has a hydraulic flow path 73 formed from the supply / discharge port 7c to the first drive chamber 4c, and the hydraulic cover 47 has a hydraulic flow path 74 formed from the supply / discharge port 7d to the second drive chamber 4d.

[0031] A gas supply pipe 11 is connected to the gas intake port 6a of the first gas cylinder 3A, and a gas exhaust pipe 13 is connected to the gas discharge port 6d of the second gas cylinder 3B. The gas discharge port 6b of the first gas cylinder 3A and the gas intake port 6c of the second gas cylinder 3B are connected to each other by a gas communication pipe 12. This allows gas to be supplied from the compression chamber 3a of the first gas cylinder 3A to the compression chamber 3b of the second gas cylinder 3B. The gas supply pipe 11 and the gas exhaust pipe 13 are provided with check valves 1a and 1d, respectively, and the gas communication pipe 12 is provided with check valves 1b and 1c.

[0032] The gas piston 33 of the first gas cylinder 3A and the gas piston 37 of the second gas cylinder 3B move alternately. When the gas piston 33 of the first gas cylinder 3A descends, gas flows from the gas supply pipe 11 through the gas suction passage 61 into the compression chamber 3a. When the gas piston 33 of the first gas cylinder 3A ascends and the gas piston 37 of the second gas cylinder 3B descends, gas flows out of the compression chamber 3a of the first gas cylinder 3A through the gas discharge passage 62 and into the compression chamber 3b of the second gas cylinder 3B through the gas communication pipe 12 and the gas suction passage 63. At this time, the gas is compressed due to the difference in area between the compression chambers 3a and 3b. That is, when the pressure in compression chamber 3a is lower than the pressure in compression chamber 3b, gas is compressed in compression chamber 3a, gas discharge passage 62, and the portion of gas communication pipe 12 upstream of check valve 1b, and when the pressure in compression chamber 3a becomes equal to or higher than the pressure in compression chamber 3b, gas is compressed in compression chamber 3a, gas discharge passage 62, gas communication pipe 12, gas suction passage 63, and compression chamber 3b. When gas piston 37 of second gas cylinder 3B rises, gas in compression chamber 3b is compressed to at least the pressure downstream of check valve 1d, and the compressed gas flows out through gas discharge passage 64 to gas exhaust pipe 13.

[0033] The supply / discharge port 7a of the first hydraulic cylinder 4A and the supply / discharge port 7c of the second hydraulic cylinder 4B are connected to supply / discharge pipes 14, 16, respectively. The supply / discharge port 7b of the first hydraulic cylinder 4A and the supply / discharge port 7d of the second hydraulic cylinder 4B are connected to each other by a hydraulic communication pipe 15. Therefore, the second drive chamber 4b of the first hydraulic cylinder 4A and the second drive chamber 4d of the second hydraulic cylinder 4B are communicated with each other via a hydraulic flow path 72, the hydraulic communication pipe 15, and a hydraulic flow path 74.

[0034] The diameter of the hydraulic piston 44 of the first hydraulic cylinder 4A and the diameter of the hydraulic piston 48 of the second hydraulic cylinder 4B are equal. Therefore, the stroke of the hydraulic piston 44 and the gas piston 33 in the first structure 2A and the stroke of the hydraulic piston 48 and the gas piston 37 in the second structure 2B are equal. However, the diameter of the hydraulic piston 44 of the first hydraulic cylinder 4A and the diameter of the hydraulic piston 48 of the second hydraulic cylinder 4B may be different, and the stroke of the hydraulic piston 44 and the gas piston 33 in the first structure 2A and the stroke of the hydraulic piston 48 and the gas piston 37 in the second structure 2B may be different.

[0035] When hydraulic oil is supplied from the supply and discharge piping 14 to the first drive chamber 4a of the first hydraulic cylinder 4A through the hydraulic flow path 71, the hydraulic piston 44 in the first structure 21 moves down together with the gas piston 33, and hydraulic oil is supplied from the second drive chamber 4b of the first hydraulic cylinder 4A to the second drive chamber 4d of the second hydraulic cylinder 4B through the hydraulic flow path 72, the hydraulic communicating piping 15, and the hydraulic flow path 74. When hydraulic oil is supplied to the second drive chamber 4d, the hydraulic piston 48 in the second structure 22 moves up together with the gas piston 37, and hydraulic oil flows out from the first drive chamber 4c to the supply and discharge piping 16 through the hydraulic flow path 73.

[0036] Conversely, when hydraulic oil is supplied from the supply and discharge piping 16 to the first drive chamber 4c of the second hydraulic cylinder 4B through the hydraulic flow path 73, the hydraulic piston 48 in the second structure 22 moves down together with the gas piston 37, and hydraulic oil is supplied from the second drive chamber 4d of the second hydraulic cylinder 4B to the second drive chamber 4b of the first hydraulic cylinder 4A through the hydraulic flow path 74, the hydraulic communicating piping 15, and the hydraulic flow path 72. When hydraulic oil is supplied to the second drive chamber 4b, the hydraulic piston 44 in the first structure 21 moves up together with the gas piston 33, and hydraulic oil flows out from the first drive chamber 4a to the supply and discharge piping 14 through the hydraulic flow path 71.

[0037] Furthermore, in this embodiment, as shown in Figures 2 and 3, two cooling flow paths 81 are formed in the gas cover 32 of the first gas cylinder 3A, and as shown in Figure 4, two cooling flow paths 82 are formed in the gas cover 36 of the second gas cylinder 3B. However, one or three or more cooling flow paths 81 may be formed in the gas cover 32, and one or three or more cooling flow paths 82 may be formed in the gas cover 36.

[0038] With respect to the gas cover 32 of the first gas cylinder 3A, the above-mentioned gas inlet passage 61 and gas discharge passage 62 extend in opposite directions from the center of the first gas cylinder 3A, as shown in Fig. 3. The two cooling passages 81 extend on both sides of the gas inlet passage 61 and gas discharge passage 62 along the gas inlet passage 61 and gas discharge passage 62, in other words, parallel to the gas inlet passage 61 and gas discharge passage 62. In other words, each cooling passage 81 forms cooling ports 81a, 81b on the end surface of the gas cover 32 facing radially outward.

[0039] However, each cooling passage 81 does not necessarily have to be linear, and may be bent along the way. In this case, one or both of the cooling ports 81 a and 81 b may be located on the upper surface of the gas cover 32.

[0040] A cooling medium flows through each cooling flow path 81. The cooling medium is not particularly limited, but may be, for example, water or brine. In this embodiment, a supply pipe 91 is connected to a cooling port 81a located near the gas intake port 6a, and an exhaust pipe 92 is connected to a cooling port 81b located near the gas discharge port 6b. In other words, the cooling port 81a is an inlet port, and the cooling port 81b is an outlet port. The cooling medium is supplied from the supply pipe 91 to the cooling flow path 81, and the cooling medium heated by flowing through the cooling flow path 81 is discharged from the cooling flow path 81 to the exhaust pipe 92. However, contrary to this embodiment, the supply pipe 91 may be connected to the cooling port 81b, and the exhaust pipe 92 may be connected to the cooling port 81a.

[0041] With respect to the gas cover 36 of the second gas cylinder 3B, the above-mentioned gas inlet passage 63 and gas discharge passage 64 extend in opposite directions from the center of the second gas cylinder 3B, as shown in Fig. 4. The two cooling passages 82 extend on both sides of the gas inlet passage 63 and gas discharge passage 64 along the gas inlet passage 63 and gas discharge passage 64, in other words, parallel to the gas inlet passage 63 and gas discharge passage 64. In other words, each cooling passage 82 forms cooling ports 82a, 82b on the end surface of the gas cover 36 facing radially outward.

[0042] However, each cooling passage 82 does not necessarily have to be linear, and may be bent along the way. In this case, one or both of the cooling ports 82a, 82b may be located on the upper surface of the gas cover 36.

[0043] A cooling medium flows through each cooling flow path 82. The cooling medium is not particularly limited, but may be, for example, water or brine. In this embodiment, a supply pipe 93 is connected to a cooling port 82a located near the gas intake port 6c, and an exhaust pipe 94 is connected to a cooling port 82b located near the gas discharge port 6d. In other words, the cooling port 82a is an inlet port, and the cooling port 82b is an outlet port. The cooling medium is supplied from the supply pipe 93 to the cooling flow path 82, and the cooling medium heated by flowing through the cooling flow path 82 is discharged from the cooling flow path 82 to the exhaust pipe 94. However, contrary to this embodiment, the supply pipe 93 may be connected to the cooling port 82b, and the exhaust pipe 94 may be connected to the cooling port 82a.

[0044] As described above, in the gas booster 1 of this embodiment, the gas cover 32 of the first gas cylinder 3A has the cooling passage 81 through which a cooling medium flows, and the gas cover 36 of the second gas cylinder 3B has the cooling passage 82 through which a cooling medium flows, thereby enabling cooling of the gas covers 32, 36. Therefore, in the first gas cylinder 3A, the temperature rise of the gas flowing into the compression chamber 3a through the gas intake passage 61 and the gas flowing out of the compression chamber 3a through the gas discharge passage 62 can be suppressed. In the second gas cylinder 3B, the temperature rise of the gas flowing into the compression chamber 3b through the gas intake passage 63 and the gas flowing out of the compression chamber 3b through the gas discharge passage 64 can be suppressed. By suppressing the temperature rise of the gas flowing into the compression chambers 3a, 3b, the compression efficiency is improved and the gas discharge amount of the gas booster 1 is increased. Furthermore, by suppressing the temperature rise of the gas flowing out of the compression chambers 3a, 3b, a decrease in the strength of the gas communication pipe 12 connected to the gas discharge passage 62 and the gas discharge pipe 13 connected to the gas discharge passage 64 can be prevented.

[0045] Furthermore, in this embodiment, the cooling flow path 81 in the gas cover 32 of the first gas cylinder 3A extends along the gas intake flow path 61 and the gas discharge flow path 62, and the cooling flow path 82 in the gas cover 36 of the second gas cylinder 3B extends along the gas intake flow path 63 and the gas discharge flow path 64, so that the gas covers 32, 36 can be cooled efficiently.

[0046] <Modifications> The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present disclosure.

[0047] For example, as shown in Figure 5, an H-shaped cooling passage 83 may be formed in the gas cover 32 of the first gas cylinder 3A. This configuration allows for particularly efficient cooling of the gas cover 32. This modification can also be applied to the gas cover 36 of the second gas cylinder 3B.

[0048] More specifically, the cooling flow path 83 includes a pair of straight portions 84, 85 that extend along the gas inlet flow path 61 and the gas discharge flow path 62 on both sides of the gas inlet flow path 61 and the gas discharge flow path 62, and a junction portion 86 that connects the centers of the straight portions 84, 85. The straight portion 84 forms a cooling port 83a on an end face that faces radially outward of the gas cover 32, and the straight portion 85 forms a cooling port 83b on an end face that faces radially outward of the gas cover 32. A supply pipe 91 is connected to the cooling port 83a, and an exhaust pipe 92 is connected to the cooling port 83b.

[0049] Contrary to the above embodiment, the supply / discharge port 7a of the first hydraulic cylinder 4A and the supply / discharge port 7c of the second hydraulic cylinder 4B may be connected to each other by a hydraulic communication pipe 15, and the supply / discharge port 7b of the first hydraulic cylinder 4A and the supply / discharge port 7d of the second hydraulic cylinder 4B may be connected to supply / discharge pipes 14, 16, respectively.

[0050] Furthermore, the compression chamber 3a of the first gas cylinder 3A and the compression chamber 3b of the second gas cylinder 3B may be connected in parallel to compress the gas in a single stage by the gas booster 1. In this case, the sizes of the first gas cylinder 3A and the second gas cylinder 3B may be the same.

[0051] Alternatively, the gas booster 1 may be a uniaxial type in which a hydraulic cylinder is disposed between two gas cylinders. In this configuration, the hydraulic piston of the hydraulic cylinder is connected to the gas pistons of both gas cylinders by two rods. When the gas booster 1 is a uniaxial type, the compression chambers of the two gas cylinders may be connected in series so that the gas booster 1 compresses the gas in two stages, or the compression chambers of the two gas cylinders may be connected in parallel so that the gas booster 1 compresses the gas in one stage.

[0052] <Summary> In a first aspect, the present disclosure provides a gas booster comprising: a gas cylinder including a gas cylinder tube, a gas cover closing one opening of the gas cylinder tube, and a gas piston disposed in the gas cylinder tube to form a compression chamber between itself and the gas cover; a hydraulic cylinder including a hydraulic cylinder tube, a pair of hydraulic covers closing openings on both sides of the hydraulic cylinder tube, and a hydraulic piston disposed in the hydraulic cylinder tube to form a pair of drive chambers between itself and the pair of hydraulic covers; and a rod connecting the hydraulic piston and the gas piston, wherein the gas cover has a gas intake flow path and a gas discharge flow path communicating with the compression chamber, and a cooling flow path through which a cooling medium flows.

[0053] According to the above configuration, the gas cover has a cooling passage through which a cooling medium flows, allowing the gas cover to be cooled. This makes it possible to suppress the temperature rise of the gas flowing into the compression chamber through the gas intake passage and the gas flowing out of the compression chamber through the gas discharge passage. By suppressing the temperature rise of the gas flowing into the compression chamber, compression efficiency improves and the gas discharge amount of the gas booster increases. Furthermore, by suppressing the temperature rise of the gas flowing out of the compression chamber, it is possible to prevent a decrease in the strength of the gas piping connected to the gas discharge passage.

[0054] As a second aspect, in the first aspect, the cooling passage may extend along the gas intake passage and the gas discharge passage. With this configuration, the gas cover can be efficiently cooled.

[0055] In a third aspect, in the first aspect, the gas inlet passage and the gas discharge passage may extend in opposite directions from the center of the gas cylinder, and the cooling passage may include a pair of linear portions extending along the gas inlet passage and the gas discharge passage on both sides of the gas inlet passage and the gas discharge passage, and a junction portion connecting the central portions of the pair of linear portions. With this configuration, the gas cover can be cooled particularly efficiently.

[0056] As a fourth aspect, in any one of the first to third aspects, for example, the gas cover may be partially fitted into the gas cylinder tube.

[0057] 1 Gas booster 11, 12, 13 Gas piping 2A First structure 2B Second structure 3A, 3B Gas cylinder 3a, 3b Compression chamber 31, 35 Gas cylinder tube 32, 36 Gas cover 33, 37 Gas piston 4A, 4B Hydraulic cylinder 4a, 4b, 4c, 4d Drive chamber 41, 45 Hydraulic cylinder tube 42, 43, 46, 47 Hydraulic cover 44, 48 Hydraulic piston 51, 52 Rod 61, 63 Gas intake passage 62, 64 Gas discharge passage 81, 82, 83 Cooling passage 84, 85 Straight section 86 Confluence section

Claims

1. A gas booster comprising: a gas cylinder including a gas cylinder tube, a gas cover closing one opening of the gas cylinder tube, and a gas piston disposed within the gas cylinder tube to form a compression chamber between the gas cover and the gas cover; a hydraulic cylinder including a hydraulic cylinder tube, a pair of hydraulic covers closing openings on both sides of the hydraulic cylinder tube, and a hydraulic piston disposed within the hydraulic cylinder tube to form a pair of drive chambers between the pair of hydraulic covers; and a rod connecting the hydraulic piston and the gas piston, wherein the gas cover has a gas intake flow path and a gas discharge flow path communicating with the compression chamber, and a cooling flow path through which a cooling medium flows.

2. A gas booster as set forth in claim 1, wherein said cooling passages extend along said gas intake passage and said gas discharge passage.

3. A gas booster as set forth in claim 1, wherein the gas intake passage and the gas discharge passage extend in opposite directions from the center of the gas cylinder, and the cooling passage includes a pair of straight sections extending along the gas intake passage and the gas discharge passage on both sides of the gas intake passage and the gas discharge passage, and a confluence section connecting the central sections of the pair of straight sections.

4. A gas booster according to any one of claims 1 to 3, wherein the gas cover is partially fitted within the gas cylinder tube.

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