Gas compression system, floating body

Abstract

To minimize gas leakage while keeping costs down. [Solution] The gas compression system comprises a gas supply unit capable of supplying gas, a compressor equipped with a compression mechanism for compressing gas from the gas supply unit, a sealing unit for suppressing gas leakage from the operating part of the compression mechanism, a gas supply destination to which the gas compressed by the compressor is supplied, and a leak gas pumping unit for pumping leaked gas from the sealing unit to the gas supply destination or the inlet side of the compressor. It is equipped with.

Description

Technical Field

[0001] The present disclosure relates to a gas compression system and a floating body.

Background Art

[0002] In ships and facilities equipped with tanks for storing liquefied gas, there are often pumps for transferring the liquefied gas and compressors for compressing the vaporized gas. For example, Patent Document 1 discloses a configuration including a reliquefaction device for reliquefying boil-off gas generated by evaporation of liquefied gas in a tank. Such a reliquefaction device includes a compressor for compressing the boil-off gas in order to reliquefy the boil-off gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the above-mentioned compressor and pump, compressed gas inside or compressed gas vaporized from pressurized liquefied gas may leak slightly from the seal part of the compressor or pump. However, there is a problem that if an attempt is made to stop the gas leakage or remove the leaked gas, the device becomes complicated and the cost increases.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a gas compression system and a floating body that can suppress gas leakage while suppressing an increase in cost.

Means for Solving the Problems

[0006] To solve the above problems, the gas compression system according to this disclosure comprises a gas supply unit, a compressor, a gas supply destination, and a leak gas pumping unit. The gas supply unit is capable of supplying gas. The compressor comprises a compression mechanism and a seal unit. The compression mechanism compresses the gas from the gas supply unit. The seal unit suppresses the leakage of the gas from the operating part of the compression mechanism. The gas supply destination is supplied with the gas compressed by the compressor. The leak gas pumping unit pumps the leak gas leaked from the seal unit to the gas supply destination or to the inlet side of the compressor.

[0007] The floating body relating to this disclosure comprises a floating body body and a gas compression system as described above. [Effects of the Invention]

[0008] The gas compression system and float described herein can suppress gas leakage while keeping costs down. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of a floating body equipped with a gas compression system according to an embodiment of the present disclosure. [Figure 2] This figure shows the configuration of a gas compression system according to the first embodiment of this disclosure. [Figure 3] This figure shows the configuration of the leak gas pumping section of the gas compression system according to the first embodiment of this disclosure. [Figure 4] This figure shows the configuration of the leak gas pumping section of the gas compression system according to the second embodiment of this disclosure. [Figure 5] This figure shows the configuration of the leak gas pumping section of a gas compression system according to the third embodiment of this disclosure. [Figure 6] This figure shows the configuration of a gas compression system according to a modified example of the first embodiment of the present disclosure. [Figure 7] This figure shows the configuration of the leak gas pumping section of a gas compression system according to the fourth embodiment of this disclosure. [Modes for carrying out the invention]

[0010] <First Embodiment> Hereinafter, the gas compression system and floating body according to the embodiments of this disclosure will be described with reference to Figures 1 to 7. (Overall structure of the floating structure) As shown in Figure 1, the floating body 1 in this embodiment comprises at least a floating body body 2 and a gas compression system 10A. In this embodiment, the floating body 1 is described as a vessel capable of navigation using a main engine, etc., but it is not limited to a vessel as long as it is a floating body equipped with a gas compression system 10A. When the floating body 1 is a vessel, the type of vessel is not limited to a specific type, and examples include liquefied gas carriers, ferries, RORO ships, car carriers, passenger ships, etc. Examples of floating bodies 1 that are not vessels include FSUs (Floating Storage Units) and FSRUs (Floating Storage and Regasification Units).

[0011] (Structure of the floating body) The floating hull body 2 has a pair of side panels 3A and 3B that form its outer shell, a bottom 4, and an upper deck 5. The side panels 3A and 3B each have a pair of side platings that form the port and starboard sides, respectively. The bottom 4 has bottom platings that connect these side panels 3A and 3B. The upper deck 5 is a full-length deck that is exposed to the outside. The floating hull body 2 has a superstructure 7 with living quarters formed on the upper deck 5, for example, on the stern side 2b. Note that the position of the superstructure 7 is merely an example; for example, the superstructure 7 may be placed on the bow side 2a of the floating hull body 2.

[0012] (Gas compression system configuration) Figure 2 shows the configuration of a gas compression system according to the first embodiment of this disclosure. As shown in Figure 2, the gas compression system 10A compresses gas in a gaseous state. The gas compression system 10A includes a gas supply unit 11, a knockout drum 13, a compressor 20, a condenser 15, an expansion valve 16, and a leak gas pumping unit 40A. In this embodiment, the knockout drum 13, compressor 20, condenser 15, and expansion valve 16 of the gas compression system 10A constitute a reliquefaction device 19 that reliquefies boil-off gas, which is gaseous gas generated in the tank 12, which is the gas supply unit 11. As shown in Figure 1, the reliquefaction device 19 is provided, for example, on the upper deck 5 of the floating body 2. The reliquefaction device 19 may also be provided inside the floating body 2.

[0013] (Gas Supply Department) The gas supply unit 11 is capable of supplying gas in a gaseous state. In this embodiment, the gas supply unit 11 is a tank 12 capable of storing liquefied gas. This tank 12 is located inside the floating body 2. The tank 12 may also be located on the upper deck 5 of the floating body 2. The tank 12 may store liquefied gas as fuel for a combustion device located inside the floating body 2, or it may store liquefied gas as cargo. Figure 1 shows an example in which multiple tanks 12 are located on the upper deck 5 and inside the floating body 2.

[0014] Tank 12 can store liquefied gases such as liquefied ammonia, liquefied petroleum gas (LPG), and liquefied natural gas (LNG). The liquid phase at the bottom of Tank 12 stores liquid. The gas phase at the top of Tank 12 stores boil-off gas, which is generated when the liquid inside Tank 12 evaporates due to heat input from the outside.

[0015] The gas supply unit 11 is connected to the compressor 20 via the gas supply line 101. The gas supply line 101 supplies gas from the gas supply unit 11 to the compressor 20. The knockout drum 13 is located in the middle of the gas supply line 101. The knockout drum 13 temporarily stores the gas from the gas supply unit 11 and separates the droplets contained in the gas.

[0016] FIG. 3 is a diagram showing the configuration of a leak gas pumping unit of a gas compression system according to the first embodiment of the present disclosure. (Compressor) As shown in FIG. 3, the compressor 20 includes a compression mechanism 21, a housing 22, a crankshaft 26, and a drive unit 27. The compressor 20 includes a compression mechanism 21, a crankshaft 26, and a drive unit 27 in a substantially cylindrical housing 22 extending in the axial direction Da along the central axis C.

[0017] (Compression mechanism) The compression mechanism 21 compresses the gas supplied through the gas supply line 101. The compression mechanism 21 in this embodiment includes a first compression mechanism 21A and a second compression mechanism 21B. That is, the compressor 20 in this embodiment constitutes a so-called two-stage compressor that sequentially compresses the gas with the first compression mechanism 21A and the second compression mechanism 21B.

[0018] Each of the first compression mechanism 21A and the second compression mechanism 21B includes a cylinder 23, a piston 24, and a connecting rod 25. The cylinders 23 are each formed in a cylindrical shape centered on the central axis C. Hereinafter, the direction in which the central axis C extends is referred to as the axial direction Da.

[0019] (Cylinder) The cylinder 23 is provided in the compression chamber 22c of the housing 22. The compression chamber 22c is defined between an end wall 221 that closes the tip of the housing 22 in the axial direction Da and a first partition wall 222 provided in the housing 22 and separated from the end wall 221 in the axial direction Da.

[0020] (Piston) The piston 24 is mounted within the cylinder 23 so as to be reciprocable in the axial direction Da. A shaft 24s extending in the axial direction Da is integrally provided with the piston 24. The connecting rod 25 connects the shaft 24s of the piston 24 to the crankshaft 26. One end of the connecting rod 25 is rotatably connected to the shaft 24s. The other end of the connecting rod 25 is rotatably connected to the crankshaft 26 at an eccentric position from the rotation axis 26r of the crankshaft 26. Each connecting rod 25 of the first compression mechanism 21A and the second compression mechanism 21B is connected to a single crankshaft 26.

[0021] (crank axle) The crankshaft 26 is rotationally driven around its axis of rotation 26r by a drive unit 27 such as a motor. The rotation of the crankshaft 26 in the first compression mechanism 21A and the second compression mechanism 21B is converted into reciprocating motion of the piston 24 in the axial direction Da by the connecting rod 25. In this embodiment, the compressor 20 is exemplified as a so-called horizontally opposed type, in which the central axis C of the cylinder 23 of the first compression mechanism 21A and the central axis C of the cylinder 23 of the second compression mechanism 21B are arranged to face opposite directions in the horizontal plane. The number and arrangement of the cylinders 23 of the compressor 20 may be in other forms as appropriate.

[0022] (Operation of the first and second compression mechanisms) In the first compression mechanism 21A and the second compression mechanism 21B, the piston 24 reciprocates in the axial direction Da, thereby compressing the gas supplied through the gas supply line 101 in the compression chamber 22c.

[0023] The gas compressed in the compression chamber 22c of the first compression mechanism 21A is introduced into the compression chamber 22c of the second compression mechanism 21B through the connecting line 102. An intercooler 14 is provided along the connecting line 102 to cool the gas from the first compression mechanism 21A. The gas introduced into the compression chamber 22c of the second compression mechanism 21B is further compressed in the second compression mechanism 21B.

[0024] (condenser) As shown in Figure 2, the condenser 15 is connected to the compression chamber 22c of the second compression mechanism 21B of the compressor 20 via the compressed gas flow line 103. The condenser 15 condenses the gas compressed in the compression chamber 22c of the second compression mechanism 21B, which is supplied via the compressed gas flow line 103. (Expansion valve) The expansion valve 16 is connected to the condenser 15 via a connection line 104. The expansion valve 16 expands the gas condensed in the condenser 15, which is supplied through the connection line 104. The expansion valve 16 is connected to the tank 12 (gas supply unit 11) via a circulation line 105. The gas expanded in the expansion valve 16 is returned to the tank 12 through the circulation line 105. In other words, in this embodiment, the gas supply destination to which the gas compressed by the compressor 20 is supplied is the tank 12, which serves as the gas supply unit 11.

[0025] (Seal part) As shown in Figure 3, in the compressor 20 of this embodiment, each of the first compression mechanism 21A and the second compression mechanism 21B is equipped with a seal portion 30. The seal portion 30 suppresses gas leakage from the operating parts of each of the first compression mechanism 21A and the second compression mechanism 21B. In this embodiment, the seal portion 30 includes, for example, a first seal portion 31, a second seal portion 32, and a third seal portion 33. The first seal portion 31, the second seal portion 32, and the third seal portion 33 are spaced apart in the axial direction Da along the central axis C. The first seal portion 31, the second seal portion 32, and the third seal portion 33 are arranged in this order so as to move away from the piston 24 in sequence.

[0026] The first seal portion 31 is held by the first partition wall 222. The second seal portion 32 is held by the second partition wall 223 provided inside the housing 22. The third seal portion 33 is held by the third partition wall 224 provided inside the housing 22. Each of the first seal portion 31, the second seal portion 32, and the third seal portion 33 is annular in shape, and a shaft 24s is inserted through its radially inward side with a clearance of a predetermined dimension or less. These first seal portion 31, the second seal portion 32, and the third seal portion 33 prevent gas from leaking out of the compression chamber 22c through the gap between the shaft 24s, which penetrates the compression chamber 22c and extends to the outside of the compression chamber 22c, and the compression chamber 22c.

[0027] (First bulkhead chamber, second bulkhead chamber) Inside the housing 22, a first isolation chamber 225 and a second isolation chamber 226 are formed. The first isolation chamber 225 is formed within the housing 22 between the first partition wall 222 and the second partition wall 223. Each of the first isolation chambers 225 of the first compression mechanism 21A and the second compression mechanism 21B is connected to the knockout drum 13 via the first leak line 121. A portion of the gas that has passed through the first seal section 31 from the compression chamber 22c is sent from the first isolation chamber 225 to the knockout drum 13 on the suction side of the compressor 20.

[0028] The second isolation chambers 226 of the first compression mechanism 21A and the second compression mechanism 21B are formed within the housing 22 between the second partition wall 223 and the third partition wall 224. A second leak line 122 is connected to each of the second isolation chambers 226 of the first compression mechanism 21A and the second compression mechanism 21B. The second leak line 122 connected to the second isolation chamber 226 of the first compression mechanism 21A and the second leak line 122 connected to the second isolation chamber 226 of the second compression mechanism 21B merge into a single second leak line 122. A check valve 123 is provided in the middle of the second leak line 122.

[0029] (Leak gas pumping section) The leak gas pumping unit 40A pumps the leak gas leaking from the seal section 30 to the gas supply destination or the inlet side of the compressor 20. In this embodiment, the leak gas pumping unit 40A pumps the gas (leak gas) that has leaked through the second leak line 122, passing through the first seal section 31 and the second seal section 32 of the seal section 30, to the inlet side of the compressor 20, up to the second isolation chamber 226.

[0030] In this embodiment, the leak gas pumping unit 40A includes a gas supply line 101, a branch line 115, a second leak line 122, a blower 40, and a return line 117.

[0031] (Branching line) The branch line 115 branches off from the gas supply line 101. In this embodiment, the branch line 115 branches off from a knockout drum 13 located in the middle of the gas supply line 101. The branch line 115 is connected to the blower 40. The second leak line 122 is connected in the middle of the branch line 115.

[0032] (Blower) The blower 40 is connected to the knockout drum 13, which is the inlet side of the compressor 20, via the return line 117. The blower 40 draws out the gas stored in the knockout drum 13 through the branch line 115. This creates a negative pressure in the branch line 115 due to the flow of gas drawn out from the knockout drum 13. When this negative pressure is created, the leak gas in the second isolation chamber 226 is drawn out through the second leak line 122. The leak gas drawn out into the second leak line 122 merges with the gas in the branch line 115 and is then pumped by the blower 40 through the return line 117 to the knockout drum 13. In other words, the blower 40 pumps the gas flowing from the gas supply line 101 into the branch line 115, along with the leak gas in the second leak line 122, to the inlet side of the compressor 20.

[0033] (Effects and Benefits) In the gas compression system 10A and floating body 1 of the above embodiment, the leak gas supply unit 40A pumps the leak gas that leaks from the operating part of the compression mechanism 21 through the seal part 30 to the inlet side of the compressor 20. With such a leak gas supply unit 40A, there is no need to stop the gas leakage by the seal part 30 or to abate the leaked gas. Therefore, the gas compression system 10A can be made into a simple configuration. Thus, gas leakage to the outside of the gas compression system 10A can be suppressed while keeping the complexity of the device down. As a result, gas leakage can be suppressed while keeping the cost increase down.

[0034] Furthermore, in the above embodiment, the leak gas pumping unit 40A includes a blower 40 that pumps the gas flowing from the gas supply line 101 to the branch line 115 together with the leak gas from the second leak line 122. With this configuration, the blower 40 sucks up the leak gas that has leaked out of the seal section 30 flowing through the second leak line 122. Therefore, with a simple configuration, the leak gas that has leaked out through the seal section 30 can be sucked up and pumped to the inlet side of the compressor 20.

[0035] Furthermore, in the above embodiment, since the gas supply unit 11 is a tank 12, if the boil-off gas generated by the evaporation of liquefied gas stored in the tank 12 is configured to be compressible by the compressor 20, the leakage of boil-off gas to the outside of the gas compression system 10A can be suppressed by the leak gas pumping unit 40A.

[0036] <Second Embodiment> Next, a second embodiment of the gas compression system and float according to this disclosure will be described. In the second embodiment described below, only the configuration of the gas compression system differs from that of the first embodiment, so the same reference numerals are used for the same parts as in the first embodiment, and redundant explanations will be omitted. Figure 4 shows the configuration of the leak gas pumping section of a gas compression system according to the second embodiment of this disclosure. (Leak gas pumping section) As shown in Figure 4, the leak gas pumping section 40B of the gas compression system 10B of this second embodiment includes a gas supply line 101, a branch line 116, a second leak line 122, an ejector 41, a booster section 42, and a return line 118.

[0037] (Branching line) The branch line 116 branches off from the gas supply line 101. In this embodiment, the branch line 116 branches off from a knockout drum 13 located in the middle of the gas supply line 101. The branch line 116 is connected to the ejector 41.

[0038] (Booster booster) The pressure boosting unit 42 is located in the middle of the branch line 116. The pressure boosting unit 42 increases the pressure of the gas flowing through the branch line 116. The pressure boosting unit 42 is located upstream of the ejector 41 in the direction of gas flow in the branch line 116. A blower can be used as the pressure boosting unit 42. Alternatively, a gas pump may be used as the pressure boosting unit 42 instead of a blower.

[0039] (Ejector) The ejector 41 is connected to a second leak line 122. The ejector 41 draws in leaked gas from the seal section 30 through the second leak line 122 by the negative pressure generated by the gas flow in the branch line 116. The ejector 41 is connected to the knockout drum 13, which is the inlet side of the compressor 20, via a return line 118.

[0040] (Operation of the leak gas pumping unit) In this leak gas pumping section 40B, the boosting section 42 draws out the gas stored in the knockout drum 13 through the branch line 116. This creates a negative pressure inside the ejector 41 due to the gas flow in the branch line 116, which has been boosted by being drawn out of the knockout drum 13 by the boosting section 42. As a result, the leak gas in the second isolation chamber 226 is drawn into the ejector 41 through the second leak line 122. The leak gas drawn out through the second leak line 122 merges with the gas in the branch line 116 inside the ejector 41 and is pumped back to the knockout drum 13 through the return line 118. In other words, the ejector 41 pumps the gas flowing from the gas supply line 101 into the branch line 116, along with the leak gas from the second leak line 122, towards the inlet side of the compressor 20.

[0041] (Effects and Benefits) In the gas compression system 10B of the second embodiment described above, similar to the first embodiment, the leak gas pumping unit 40B pumps the leak gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 to the inlet side of the compressor 20. With such a leak gas pumping unit 40B, it is possible to suppress gas leakage to the outside of the compressor 20 while keeping the complexity of the device down. As a result, gas leakage can be suppressed while keeping the increase in cost down.

[0042] Furthermore, in the second embodiment described above, the ejector 41 sucks in the leaked gas that has leaked from the seal portion 30 through the second leak line 122 by the negative pressure generated by the gas flow in the branch line 116. Therefore, the ejector 41, with its simple configuration, can suck in the leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal portion 30 and pump it to the inlet side of the compressor 20.

[0043] Furthermore, in the second embodiment described above, a pressure boosting unit 42, located upstream of the ejector 41 in the gas flow direction of the branch line 116, boosts the pressure of the gas flowing through the branch line 116. This increases the negative pressure generated by the ejector 41, allowing for more efficient suction of leaked gas leaking from the seal section 30.

[0044] <Third Embodiment> Next, a third embodiment of the gas compression system and float according to this disclosure will be described. In the third embodiment described below, only the configuration of the gas compression system differs from that of the first embodiment, so the same reference numerals are used for the same parts as in the first and second embodiments, and redundant explanations will be omitted.

[0045] Figure 5 shows the configuration of the leak gas pumping section of a gas compression system according to the third embodiment of this disclosure. (Leak gas pumping section) As shown in Figure 5, the leak gas supply section 40C of the gas compression system 10C in this embodiment includes a leak line 125 and a blower 52.

[0046] (Leakline) One end of the leak line 125 is connected to the second isolation chamber 226 of the first compression mechanism 21A and the second compression mechanism 21B, respectively. The leak line 125 connected to the second isolation chamber 226 of the first compression mechanism 21A and the leak line 125 connected to the second isolation chamber 226 of the second compression mechanism 21B merge into a single leak line 125, which is connected to the blower 52. A check valve 123 is provided in the middle of the leak line 125.

[0047] (Blower) The blower 52 is connected to the knockout drum 13, which is the inlet side of the compressor 20, via the return line 119. The blower 52 draws in the leak gas leaking from the seal section 30 through the leak line 125. This draws out the leak gas in the second isolation chamber 226 through the leak line 125. The leak gas drawn into the leak line 125 is then pumped by the blower 52 through the return line 119 to the knockout drum 13.

[0048] (Effects and Benefits) In the gas compression system 10C of the third embodiment described above, similar to the first embodiment, the leak gas pumping unit 40C pumps the leak gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 to the inlet side of the compressor 20. With such a leak gas pumping unit 40C, it is possible to suppress gas leakage to the outside of the compressor 20 while keeping the complexity of the device under control. As a result, gas leakage can be suppressed while keeping the increase in cost under control.

[0049] Furthermore, in the third embodiment described above, the blower 52 sucks up the leak gas leaking from the seal portion 30 through the leak line 125. Therefore, the blower 52, with its simple configuration, can suck up the leak gas leaking from the operating part of the compression mechanism 21 through the seal portion 30 and pump it to the inlet side of the compressor 20.

[0050] (Modifications of the first to third embodiments) In the first to third embodiments described above, the leak gas sucked in the leak gas pumping sections 40A to 40C is pumped to the knockout drum 13 at the inlet of the compressor 20, but the invention is not limited to this. For example, the leak gas sucked in the leak gas pumping sections 40A to 40C may be pumped to the gas supply line 101 on the inlet side of the compressor 20.

[0051] Figure 6 shows the configuration of a gas compression system according to a modified example of the first embodiment of the present disclosure. Furthermore, as shown in Figure 6, in the gas compression system 10A of the first embodiment described above, the leak gas sucked in by the leak gas pumping unit 40A may be pumped through the pumping line 131 to the tank 12, which is the gas supply destination. In the gas compression system 10B of the second embodiment and the gas compression system 10C of the third embodiment described above, the leak gas sucked in by the leak gas pumping units 40B and 40C may also be pumped to the tank 12, which is the gas supply destination.

[0052] Furthermore, in the leak gas pumping sections 40A to 40C, the leak gas leaking from the seal section 30 was pumped to the tank 12 through the circulation line 105, but the pumping line is not limited to this. If there are other lines connected to the tank 12, those lines may be used to pump the leak gas leaking from the seal section 30.

[0053] <Fourth Embodiment> Next, a fourth embodiment of the gas compression system and float according to this disclosure will be described. In the fourth embodiment described below, only the configuration of the gas compression system differs from that of the first embodiment, so the same reference numerals are used for the same parts as in the first to third embodiments, and redundant explanations will be omitted. Figure 7 shows the configuration of the leak gas pumping section of a gas compression system according to the fourth embodiment of this disclosure. (Leak gas pumping section) As shown in Figure 7, the leak gas supply section 40D of the gas compression system 10D in this embodiment includes a compressed gas flow line 103, a second leak line 122, and an ejector 51.

[0054] (Ejector) The ejector 51 is located in the compressed gas flow line 103. The ejector 51 is positioned closer to the compressor 20 than the condenser 15 in the compressed gas flow line 103. The second leak line 122 is connected to the ejector 51.

[0055] A negative pressure is generated inside the ejector 51 due to the flow of gas compressed by the compressor 20 in the compressed gas flow line 103. As a result, the leak gas in the second isolation chamber 226 is drawn into the ejector 51 through the second leak line 122. The ejector 51 uses the negative pressure generated by the flow of gas compressed by the compressor 20 in the compressed gas flow line 103 to draw in the leak gas that has leaked from the seal section 30 through the second leak line 122. The leak gas drawn out through the second leak line 122 merges with the gas in the compressed gas distribution line 103 within the ejector 51 and is then pumped through the compressed gas distribution line 103 to the tank 12, which is the gas supply destination.

[0056] In the gas compression system 10D of the above embodiment, similar to the first embodiment, the leak gas pumping unit 40D pumps the leak gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 to the inlet side of the compressor 20. With such a leak gas pumping unit 40D, it is possible to suppress gas leakage to the outside of the compressor 20 while keeping the complexity of the device down. As a result, gas leakage can be suppressed while keeping the increase in cost down.

[0057] Furthermore, in the above embodiment, the ejector 51 uses the negative pressure generated by the flow of gas compressed by the compressor 20 through the compressed gas flow line 103 to suck in the leaked gas that has leaked from the seal portion 30 through the second leak line 122. Therefore, the ejector 51, with its simple configuration, can suck in the leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal portion 30 and pump it to the inlet side of the tank 12, which serves as the gas supply destination.

[0058] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure. In the first to fourth embodiments and their modifications described above, the tank 12, which serves as the gas supply unit 11, stores boil-off gas, which is generated by the evaporation of liquefied gas in a liquid state, as the gaseous gas. However, the tank 12 is not limited to this. The tank 12 may also store ammonia gas, natural gas, petroleum gas, or the like in a gaseous state. Furthermore, the gas supply unit 11 is not limited to the tank 12, but may be, for example, an evaporator outlet line, as long as it is capable of supplying gas in a gaseous state.

[0059] In each of the above embodiments, the compressor 20 is provided as part of the reliquefaction device 19, and the tank 12 as the gas supply unit 11 is exemplified as the gas supply destination for the gas compressed by the compressor 20, but the invention is not limited to this. Other examples of gas supply destinations for the gas compressed by the compressor 20 include, for example, a main engine, a power generation engine, a loading base, etc.

[0060] In the above embodiment, leak gas leaking from the compression chamber 22c is pumped through the second leak line 122 by the leak gas pumping unit 40A, and leak gas is also sent to the knockout drum 13 from the first leak line 121, but the embodiment is not limited to this. For example, the first leak line 121 may be omitted, and the leak gas may be recovered only by pumping through the second leak line 122 by the leak gas pumping unit 40A.

[0061] <Note> The gas compression systems 10A to 10D and the floating body 1 described in each embodiment can be understood, for example, as follows.

[0062] (1) The gas compression systems 10A to 10D according to the first embodiment include a gas supply unit 11 capable of supplying gas, a compressor 20 having a compression mechanism 21 for compressing the gas from the gas supply unit 11 and a sealing unit 30 for suppressing the leakage of the gas from the operating part of the compression mechanism 21, a gas supply destination 12 to which the gas compressed by the compressor 20 is supplied, and leak gas pumping units 40A to 40D for pumping leak gas leaked from the sealing unit 30 to the gas supply destination 12 or to the inlet side of the compressor 20.

[0063] Such leak gas pumping sections 40A to 40D can suppress gas leakage from the gas compression system 10A to the outside while keeping the complexity of the equipment down. As a result, gas leakage can be suppressed while keeping cost increases down.

[0064] (2) The gas compression system 10A according to the second embodiment is the gas compression system 10A of (1), wherein the leak gas pumping unit 40A comprises a gas supply line 101 through which the gas supplied from the gas supply unit 11 to the compressor 20 flows, a branch line 115 branched from the gas supply line 101, a leak line 122 through which the leak gas leaked from the seal unit 30 flows, and a blower 40 that pumps the gas flowing from the gas supply line 101 to the branch line 115 together with the leak gas in the leak line 122.

[0065] With this configuration, leak gas leaking from the operating part of the compression mechanism 21 through the seal part 30 can be sucked out and pumped to the gas supply destination 12 or the inlet side of the compressor 20 using a simple setup.

[0066] (3) A gas compression system 10B according to a third embodiment is the gas compression system 10B of (1), wherein the leak gas pumping unit 40B comprises a gas supply line 101 through which the gas supplied from the gas supply unit 11 to the compressor 20 flows, a branch line 116 branched from the gas supply line 101, a leak line 122 through which the leak gas leaked from the seal unit 30 flows, an ejector 41 that sucks the leak gas leaked from the seal unit 30 through the leak line 122 by negative pressure generated by the flow of the gas in the branch line 115, and a pressurizing unit 42 provided upstream of the ejector 41 in the direction of gas flow in the branch line 115, and pressurizing the gas flowing through the branch line 116.

[0067] With this configuration, the simple ejector 41 pressurizes the gas flowing through the branch line 116 at the pressurizing unit 42, which is located upstream of the ejector 41 in the gas flow direction of the branch line 116. This increases the negative pressure generated by the ejector 41, drawing in leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 and pumping it to the gas supply destination 12 or the inlet side of the compressor 20. Examples of the pressure boosting unit 42 include a blower and a gas pump.

[0068] (4) The gas compression system 10C according to the fourth embodiment is the gas compression system 10C of (1), wherein the leak gas pumping section 40C comprises a leak line 125 through which the leak gas leaked from the seal section 30 flows, and a blower 52 that sucks the leak gas leaked from the seal section 30 through the leak line 125.

[0069] This allows the simple blower 52 to suck up the leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 and pump it to the gas supply destination 12 or the inlet side of the compressor 20.

[0070] (5) A gas compression system 10D according to a fifth embodiment is the gas compression system 10D of (1), wherein the leak gas pumping unit 40D comprises a compressed gas flow line 103 through which the gas compressed by the compressor 20 flows, a leak line 122 through which the leak gas leaked from the seal unit 30 flows, and an ejector 51 that sucks the leak gas leaked from the seal unit 30 through the leak line 122 by the negative pressure generated by the flow of the gas in the compressed gas flow line 103.

[0071] With this configuration, the simple ejector 51 can suck up the leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 and pump it to the gas supply destination 12.

[0072] (6) The gas compression systems 10A to 10D according to the sixth embodiment are any one of the gas compression systems 10A to 10D of (1) to (5), wherein the gas supply unit 11 is a tank 12 capable of storing the liquefied gas which is the liquefied gas.

[0073] In this configuration, where the gas supply unit 11 is a tank 12, and the boil-off gas generated by the evaporation of liquefied gas stored in the tank 12 is compressed by the compressor 20, the leak gas pressurization unit 40A suppresses the leakage of gas to the outside of the gas compression system 10A.

[0074] (7) The floating body 1 according to the seventh embodiment comprises a floating body body 2 and a gas compression system 10A as described above. Examples of floating structures include liquefied gas carriers, ferries, RORO ships, car carriers, passenger ships, and other vessels, as well as FSUs (Floating Storage Units) and FSRUs (Floating Storage and Regasification Units).

[0075] As a result, leaked gas that has leaked from the operating part of the compression mechanism 21 through the seal part 30 can be pumped by the leaked gas pumping part 40A to the gas supply destination 12 or the inlet side of the compressor 20. This suppresses gas leakage to the outside of the gas compression system 10A while keeping the complexity of the device down. Consequently, gas leakage can be suppressed while keeping costs down. [Explanation of Symbols]

[0076] 1. Floating body 2. Floating body 2a bow 2b stern 3A, 3B side 4. Bottom of the ship 5 Upper Deck 7 Superstructure 8. Cargo loading compartment 10A~10D Gas Compression System 11. Gas Supply Department 12 tanks (gas supply destinations) 13 Knockout Drum 14. Intercooler 15 Capacitors 16 Expansion valve 19 Reliquefaction equipment 20 Compressors 21 Compression mechanism 21A First Compression Mechanism 21B Second Compression Mechanism 22 Housing 22c Compression Chamber 23 liters 24 pistons 24s shaft 25 Connecting Rod 26 Crankshaft 26r rotation axis 27 Drive unit 30 Seal part 31 First seal section 32 Second seal section 33 Third seal section 40,52 blower 40A~40D Leak gas pumping section 41, 51 Ejectors 42 Booster section 101 Gas supply line 102 connection lines 103 Compressed Gas Distribution Line 104 connection lines 105 Circulation Line 115, 116 Branch Line 117, 118, 119 Return lines 121 First Leak Line 122 Second Leak Line (Leak Line) 123 Check valve 125 Leak Line 131 Pressure feeding line 221 End wall 222 First bulkhead 223 Second bulkhead 224 Third Bulkhead 225 First isolation room 226 Second isolation room

Claims

1. A gas supply unit capable of supplying gas, A compressor comprising a compression mechanism for compressing the gas from the gas supply unit, and a sealing unit for suppressing the leakage of the gas from the operating part of the compression mechanism, The gas supply destination to which the gas compressed by the compressor is supplied, A leak gas pumping unit that pumps the leaked gas from the seal to the gas supply destination or the compressor inlet side, A gas compression system equipped with [the following features].

2. The aforementioned leak gas pumping unit is A gas supply line through which the gas supplied from the gas supply unit to the compressor flows, A branch line that branches off from the aforementioned gas supply line, A leak line through which the leaked gas that has leaked from the seal portion flows, The system includes a blower that pumps the gas flowing from the gas supply line to the branch line along with the leak gas from the leak line. The gas compression system according to claim 1.

3. The aforementioned leak gas pumping unit is A gas supply line through which the gas supplied from the gas supply unit to the compressor flows, A branch line that branches off from the aforementioned gas supply line, A leak line through which the leaked gas that has leaked from the seal portion flows, An ejector that uses the negative pressure generated by the gas flow in the branch line to draw in the leak gas leaking from the seal through the leak line, The ejector is provided with a booster unit located upstream of the gas flow direction in the branch line, which increases the pressure of the gas flowing through the branch line. The gas compression system according to claim 1.

4. The aforementioned leak gas pumping unit is A leak line through which the leaked gas that has leaked from the seal portion flows, The system includes a blower that sucks up the leaked gas that has leaked from the seal through the leak line. The gas compression system according to claim 1.

5. The aforementioned leak gas pumping unit is A compressed gas flow line through which the gas compressed by the compressor flows, A leak line through which the leaked gas that has leaked from the seal portion flows, The system includes an ejector that uses the negative pressure generated by the gas flow in the compressed gas distribution line to draw in the leak gas leaking from the seal through the leak line. The gas compression system according to claim 1.

6. The gas supply unit is a tank capable of storing the liquefied gas, which is the gas that has been liquefied. A gas compression system according to any one of claims 1 to 5.

7. The floating body and A gas compression system according to claim 1 or 2, comprising A floating object.

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