Floating body and gas pressure control method

Abstract

The floating body is provided with: a floating body main body; a tank provided in the floating body main body and capable of storing liquefied carbon dioxide; a supply line for supplying liquefied carbon dioxide into the tank; a discharge line for discharging liquefied carbon dioxide in the tank to the outside of the tank; a gas line connected to the tank and through which carbon dioxide gas can flow; a compressor provided in the gas line and compressing the carbon dioxide gas flowing through the gas line; and a heating unit which is provided on the upstream side of the compressor in the gas line, and which is capable of heating the carbon dioxide gas flowing through the gas line.

Description

Technical Field

[0001] The present disclosure relates to a floating body and a gas pressure control method.

[0002] This application claims priority to Japanese Patent Application No. 2022-108305 filed in Japan on July 5, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] Patent document 1 discloses a structure of a gas handling system for supplying liquefied gas from a storage tank of a bunkering ship to a fuel tank of a gas propulsion ship. The gas handling system comprises: a bunkering pipeline, a boil-off gas return pipeline, and a reliquefaction device (a bunkering management unit). The bunkering pipeline supplies the liquefied gas in the storage tank to the fuel tank. The boil-off gas return pipeline transfers the boil-off gas generated in the fuel tank to the bunkering ship during bunkering via the bunkering pipeline. The reliquefaction device reliquefies the boil-off gas in the storage tank and sends it back to adjust the internal pressure of the storage tank. In such a structure, a compressor is provided upstream of the reliquefaction device. The compressor compresses the boil-off gas in the storage tank and sends it to the reliquefaction device.

[0004] However, in ships equipped with tanks capable of storing liquefied carbon dioxide, compressors are sometimes also provided. In the tanks capable of storing liquefied carbon dioxide, the liquefied carbon dioxide evaporates inside the tanks to generate carbon dioxide gas. The compressor compresses the generated carbon dioxide gas. In the case of such ships, the compressor is used to manage the pressure inside the tanks through which the carbon dioxide gas flows and the pipes connected to the tanks.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent Application No. 2021-517878 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the case of a compressor that compresses carbon dioxide gas, the carbon dioxide gas may solidify and generate dry ice for the following reasons. That is, when the compressor is operating, for example, the flow rate of the carbon dioxide gas increases at the inlet side of the compressor. When the flow rate of the carbon dioxide gas increases, the local static pressure of the carbon dioxide gas decreases. When the local static pressure of the carbon dioxide gas decreases, the possibility of generating dry ice increases.

[0009] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a floating body and a gas pressure control method that can suppress the generation of dry ice.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the floating body disclosed in the present invention comprises: a floating body, a tank, a supply pipeline, a discharge pipeline, a gas pipeline, a compressor and a heating unit. The tank is provided on the floating body. The tank is capable of storing liquefied carbon dioxide. The supply pipeline supplies the liquefied carbon dioxide into the tank. The discharge pipeline discharges the liquefied carbon dioxide in the tank to the outside of the tank. The gas pipeline is connected to the tank and can supply carbon dioxide gas to flow. The compressor is provided on the gas pipeline. The compressor compresses the carbon dioxide gas flowing in the gas pipeline. The heating unit is provided on the upstream side of the compressor in the gas pipeline. The heating unit is capable of heating the carbon dioxide gas flowing in the gas pipeline.

[0012] The gas pressure control method disclosed in the present invention is a gas pressure management method in a floating body as described above, and includes the following steps: a step of detecting the temperature of carbon dioxide gas; a step of determining whether the temperature of the carbon dioxide gas is below a preset lower limit threshold; and a step of heating the carbon dioxide gas. In the step of detecting the temperature of the carbon dioxide gas, the temperature of the carbon dioxide gas flowing in the gas pipeline is detected. In the step of determining whether the temperature of the carbon dioxide gas is below a preset lower limit threshold, it is determined whether the detected temperature of the carbon dioxide gas is below a preset lower limit threshold. In the step of heating the carbon dioxide gas, when it is determined that the temperature of the carbon dioxide gas is below the lower limit threshold, the carbon dioxide gas flows in the gas pipeline through the heating unit.

[0013] Effects of the Invention

[0014] According to the floating body and the gas pressure control method disclosed in the present invention, the generation of dry ice can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a plan view showing a schematic structure of a floating body according to an embodiment of the present disclosure.

[0016] Figure 2 It is a side cross-sectional view showing a tank and a gas line provided in a floating body according to an embodiment of the present disclosure.

[0017] Figure 3 This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas is supplied into the tank in the floating body according to the embodiment of the present disclosure.

[0018] Figure 4 This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas is discharged to the outside of the tank in the floating body according to the embodiment of the present disclosure.

[0019] Figure 5This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas in the tank is circulated in the floating body according to the embodiment of the present disclosure.

[0020] Figure 6 It is a diagram showing a hardware configuration of a control device provided in a floating body according to an embodiment of the present disclosure.

[0021] Figure 7 This is a functional block diagram of a control device provided in a floating body according to an embodiment of the present disclosure.

[0022] Figure 8 Detailed description of the invention is a flowchart showing the steps of a method for managing gas pressure in a floating body according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] Below, refer to Figure 1 to Figure 8 The floating body and the gas pressure control method according to the embodiment of the present disclosure will be described.

[0024] (Ship structure)

[0025] Figure 1 It is a plan view showing a schematic structure of a floating body according to an embodiment of the present disclosure.

[0026] In an embodiment of the present disclosure, a ship (floating body) 1 as a floating body transports liquefied carbon dioxide. Figure 1 As shown, the ship 1 includes at least a hull 2 ​​as a floating body and a tank facility 10 .

[0027] (Structure of the hull)

[0028] The hull 2 ​​has a pair of side 3A, 3B constituting its outer shell, a bottom (not shown) and an upper deck 5. The side 3A, 3B has a pair of side outer plates forming the port and starboard sides, respectively. The bottom (not shown) has a bottom outer plate connecting these side 3A, 3B. Through this pair of side 3A, 3B and the bottom (not shown), the outer shell of the hull 2 ​​is U-shaped in a cross section orthogonal to the bow and stern direction Da. The upper deck 5 illustrated in this embodiment is a full-through deck exposed to the outside. In the hull 2, for example, an upper structure 7 having a living area is formed on the upper deck 5 on the stern 2b side. In addition, the position and size of the upper structure 7 can be appropriately changed.

[0029] A cargo loading area (cargo hold) 8 is formed in the hull 2 ​​at a position closer to the bow 2a than the upper structure 7. The cargo loading area 8 is recessed toward the bottom of the ship below the upper deck 5 and is open upward.

[0030] (Structure of tank equipment)

[0031] A plurality of tank facilities 10 are arranged in a row along the bow and stern direction Da in the cargo loading section 8. In the embodiment of the present disclosure, for example, two tank facilities 10 are arranged at intervals in the bow and stern direction Da.

[0032] Figure 2 It is a side cross-sectional view showing a tank and a gas line provided in a floating body according to an embodiment of the present disclosure.

[0033] like Figure 2 As shown, the tank facility 10 includes at least a tank 11 , a supply line 15 , a discharge line 16 , a gas line 20 , a compressor 30 , a heating unit 40 , and a control device 50 .

[0034] In this embodiment, the tank 11 is arranged on the hull 2, for example, in a cylindrical shape extending along the bow and stern direction Da. The tank 11 can store liquefied carbon dioxide L therein. The tank 11 includes a cylindrical portion 12 and an end plate portion 13. The cylindrical portion 12 extends with the bow and stern direction Da as the length direction. In this embodiment, the cylindrical portion 12 is formed into a cylindrical shape, and the cross-sectional shape orthogonal to its length direction is circular. The end plate portions 13 are respectively arranged at both end portions of the cylindrical portion 12 in the length direction. Each end plate portion 13 is hemispherical and closes the openings at both ends of the cylindrical portion 12 in the length direction. In addition, the tank 11 is not limited to a cylindrical shape, and may also be other shapes such as a sphere and a square.

[0035] The supply line 15 is used to load the liquefied carbon dioxide L supplied from a liquefied carbon dioxide supply facility on land or another ship storing liquefied carbon dioxide into the tank 11. The supply line 15 passes through the top of the tank 11 from the outside of the tank 11 and reaches the bottom of the tank 11. The front end 15a of the supply line 15 (in other words, the lower end in the up-down direction Dv) opens downward at the lower part of the tank 11.

[0036] The discharge line 16 discharges the liquefied carbon dioxide L in the tank 11 to the outside of the ship such as the liquefied carbon dioxide storage facility on land. The front end 16a of the discharge line 16 is connected to the pump 18 arranged at the lower part of the tank 11. The discharge line 16 extends upward from the front end 16a and passes through the top of the tank 11 to reach the outside of the tank 11. The pump 18 connected to the front end 16a sucks the liquefied carbon dioxide L in the tank 11 and discharges the sucked liquefied carbon dioxide L to the outside of the tank 11 through the discharge line 16.

[0037] The gas pipeline 20 can at least circulate the carbon dioxide gas G in the tank 11. The carbon dioxide gas G in the tank 11 is lower than 0°C and higher than the triple point temperature of carbon dioxide. The carbon dioxide gas G in the tank 11 is mainly the so-called boil-off gas formed by evaporation of the liquefied carbon dioxide L stored in the tank 11, and is, for example, -56°C to -10°C.

[0038] The gas line 20 includes a first pipe portion 21 , a second pipe portion 22 , a third pipe portion 23 , a fourth pipe portion 24 , a fifth pipe portion 25 , and a sixth pipe portion 26 .

[0039] The first pipe section 21 is used when the carbon dioxide gas G supplied from outside the ship is sent into the tank 11. One end 21a of the first pipe section 21 is configured to be connected to a supply pipe (not shown) for supplying carbon dioxide gas G from equipment outside the ship. The carbon dioxide gas G supplied from outside the ship is, for example, -56°C to -10°C, similar to the above-mentioned boil-off gas. The other end 21b of the first pipe section 21 is connected to one end 25a of the fifth pipe section 25 described later. An on-off valve 21v is provided in the first pipe section 21.

[0040] The second pipe section 22 is used when discharging the carbon dioxide gas G in the tank 11 to the outside of the ship. One end 22a of the second pipe section 22 is configured to be connectable to a discharge pipe (not shown) for discharging the carbon dioxide gas G to equipment outside the ship. The other end 22b of the second pipe section 22 is connected to the other end 26b of the sixth pipe section 26 described later. The second pipe section 22 is provided with an on-off valve 22v.

[0041] The third pipe section 23 is used when the carbon dioxide gas G is fed into the tank 11. One end 23a of the third pipe section 23 is connected to the top 11t of the tank 11. The other end 23b of the third pipe section 23 is connected to the other end 26b of the sixth pipe section 26 described later. The third pipe section 23 is provided with an on-off valve 23v.

[0042] The fourth pipe 24 is used to discharge the carbon dioxide gas G in the tank 11 to the outside of the tank 11. One end 24a of the fourth pipe 24 is connected to the top 11t of the tank 11. The other end 24b of the fourth pipe 24 is connected to one end 25a of the fifth pipe 25 described later. The fourth pipe 24 is provided with an on-off valve 24v.

[0043] The fifth pipe section 25 is provided between the other end 21b of the first pipe section 21, the other end 24b of the fourth pipe section 24, and the heating section 40. One end 25a of the fifth pipe section 25 is connected to the other end 21b of the first pipe section 21 and the other end 24b of the fourth pipe section 24. The other end 25b of the fifth pipe section 25 is connected to the inlet of the heating section 40. An on-off valve 25v is provided in the fifth pipe section 25. The on-off valve 25v is provided on the upstream side of the heating section 40 described later in the direction in which the carbon dioxide gas flows.

[0044] The sixth pipe portion 26 is provided between the heating portion 40 and the other end 22b of the second pipe portion 22 and the other end 23b of the third pipe portion 23. One end 26a of the sixth pipe portion 26 is connected to the outlet of the heating portion 40. The other end 26b of the sixth pipe portion 26 is connected to the other end 22b of the second pipe portion 22 and the other end 23b of the third pipe portion 23. The compressor 30 and the on-off valve 25w are provided in the middle of the sixth pipe portion 26. The on-off valve 25w is provided at a position closer to the other end 26b side than the compressor 30.

[0045] The compressor 30 compresses the carbon dioxide gas G flowing in through the fifth pipe portion 25 and the sixth pipe portion 26. The compressor 30 compresses the carbon dioxide gas G sucked in from the inlet side and discharges it to the other end 26b side of the sixth pipe portion 26. Therefore, the carbon dioxide gas G flows in the sixth pipe portion 26 from the one end 26a side to the other end 26b side.

[0046] The heating unit 40 is arranged between the fifth pipe unit 25 and the sixth pipe unit 26. That is, the heating unit 40 is arranged on the upstream side relative to the compressor 30. The heating unit 40 heats the carbon dioxide gas G flowing through the fifth pipe unit 25. As the heating unit 40, for example, a heat exchanger is used. The heating unit 40 heats the carbon dioxide gas G flowing through the fifth pipe unit 25. The heating unit 40 may heat the carbon dioxide gas G at -56°C to -10°C flowing through the fifth pipe unit 25 in a manner higher than -10°C and below the upper limit temperature of the design conditions (for example, about 80°C).

[0047] The fifth pipe portion 25 is provided with a sensor 45. The sensor 45 detects the temperature of the carbon dioxide gas G flowing through the fifth pipe portion 25. The sensor 45 outputs a signal of a detection value of the detected temperature to the control device 50.

[0048] (Application of gas pipelines)

[0049] The gas line 20 as described above has the functions of a gas supply line 20F, a gas exhaust line 20E, and a gas circulation line 20R. The gas line 20 can selectively use any one of the gas supply line 20F, the gas exhaust line 20E, and the gas circulation line 20R by switching the opening and closing valves 21v to 25v, 25w.

[0050] Figure 3 This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas is supplied into the tank in the floating body according to the embodiment of the present disclosure.

[0051] like Figure 3As shown in FIG. 1 , the gas supply line 20F is configured by closing the on-off valve 22v and the on-off valve 24v and opening the on-off valve 21v, the on-off valves 25v, 25w, and the on-off valve 23v. The gas supply line 20F is used when the carbon dioxide gas G is supplied from the outside of the tank 11 to the inside of the tank 11. In this case, the carbon dioxide gas G supplied from the outside of the tank 11 is supplied to the inside of the tank 11 via the first pipe section 21, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23. That is, the gas supply line 20F is configured by the first pipe section 21, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23.

[0052] The gas supply line 20F is used, for example, to cool the inside of the tank 11 and increase the pressure inside the tank 11 before supplying the liquefied carbon dioxide L to the tank 11. In addition, the gas supply line 20F is used, for example, to suppress the pressure inside the tank 11 from decreasing as the liquefied carbon dioxide L in the tank 11 decreases when the liquefied carbon dioxide L in the tank 11 is discharged to the outside of the tank 11 through the discharge line 16. The gas supply line 20F may be used in other ways than those described above.

[0053] When the carbon dioxide gas G is supplied to the tank 11 through the gas supply line 20F, the compressor 30 is operated to compress the carbon dioxide gas G sent to the tank 11. Thus, the pressure of the gas phase in the tank 11 can be increased according to a preset target pressure.

[0054] Figure 4 This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas is discharged to the outside of the tank in the floating body according to the embodiment of the present disclosure.

[0055] like Figure 4 As shown in FIG. 1 , the gas discharge line 20E is formed by closing the on-off valve 21v and the on-off valve 23v and opening the on-off valve 24v, the on-off valves 25v and 25w, and the on-off valve 22v. The gas discharge line 20E is used when the carbon dioxide gas G is discharged from the tank 11 to the outside of the tank 11. In this case, the carbon dioxide gas G in the tank 11 is discharged to the outside of the tank 11 via the fourth pipe part 24, the fifth pipe part 25, the sixth pipe part 26, and the second pipe part 22. That is, the gas discharge line 20E is formed by the fourth pipe part 24, the fifth pipe part 25, the sixth pipe part 26, and the second pipe part 22.

[0056] The gas discharge line 20E is used, for example, to suppress the pressure in the tank 11 from increasing due to the increase of the liquefied carbon dioxide L in the tank 11 when the liquefied carbon dioxide L is supplied to the tank 11 through the supply line 15. The gas discharge line 20E may be used in other ways than those described above.

[0057] When the carbon dioxide gas G is discharged to the outside of the tank 11 through the gas discharge line 20E, the compressor 30 is operated to compress the carbon dioxide gas G discharged to the outside of the tank 11. Thus, the carbon dioxide gas G can be efficiently discharged. Therefore, the pressure of the gas phase in the tank 11 can be efficiently managed in accordance with the preset target pressure.

[0058] Figure 5 This is a diagram showing the flow of carbon dioxide gas when the carbon dioxide gas in the tank is circulated in the floating body according to the embodiment of the present disclosure.

[0059] like Figure 5 As shown in FIG. 1 , the gas circulation line 20R is formed by closing the on-off valve 21v and the on-off valve 22v and opening the on-off valve 24v, the on-off valve 25v, the on-off valve 25w, and the on-off valve 23v. In this case, the carbon dioxide gas G in the tank 11 circulates into the tank 11 via the fourth pipe section 24, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23. That is, the gas circulation line 20R is formed by the fourth pipe section 24, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23.

[0060] The gas circulation line 20R is used when pressurizing the carbon dioxide gas G in the tank 11. In this case, the carbon dioxide gas G taken out of the tank 11 to the gas circulation line 20R outside the tank 11 is compressed by operating the compressor 30. As a result, the pressure of the carbon dioxide gas G increases. By returning the carbon dioxide gas G after the pressure increase to the tank 11, the pressure of the gas phase in the tank 11 increases. Therefore, the pressure of the gas phase in the tank 11 can be efficiently managed corresponding to the preset target pressure. In addition, the gas circulation line 20R can also be used in a manner other than the above. In addition, in the present embodiment, a reliquefaction device (not shown) that reliquefies the carbon dioxide gas G (so-called evaporated gas) generated by evaporation in the tank 11 is provided separately from the gas line 20.

[0061] As described above, when the gas line 20 is used as the gas supply line 20F, the gas discharge line 20E, and the gas circulation line 20R, the carbon dioxide gas G flowing through the fifth pipe portion 25 can be heated by the heating unit 40 on the upstream side of the compressor 30. The heating unit 40 may always heat the carbon dioxide gas G, but in this embodiment, the heating unit 40 performs heating according to the temperature of the carbon dioxide gas G on the upstream side of the compressor 30. The operation of the heating unit 40 is controlled by the control device 50.

[0062] (Hardware structure diagram)

[0063] Figure 6 It is a diagram showing a hardware configuration of a control device provided in a floating body according to an embodiment of the present disclosure.

[0064] like Figure 6 As shown, the control device 50 is a computer including a CPU 51 (Central Processing Unit), a ROM 52 (Read Only Memory), a RAM 53 (Random Access Memory), a memory 54 such as a HDD (Hard Disk Drive), and a signal transceiver module 55. The signal transceiver module 55 receives a signal of a detection value from the sensor 45.

[0065] (Functional Block Diagram)

[0066] Figure 7 This is a functional block diagram of a control device provided in a floating body according to an embodiment of the present disclosure.

[0067] like Figure 7 As shown, the control device 50 realizes the functional configurations of the signal receiving unit 71 , the heating control unit 72 , and the output unit 73 by the CPU 51 executing a program stored in a memory 54 such as a HDD.

[0068] The signal receiving unit 71 receives a signal of a detection value from the sensor 45 via the signal transceiver module 55 .

[0069] The heating control unit 72 controls the operation of the heating unit 40 based on the detection value of the sensor 45. The heating control unit 72 controls the operation and stop of the heating unit 40. The heating control unit 72 operates the heating unit 40 when the temperature of the carbon dioxide gas G flowing through the fifth pipe part 25 detected by the sensor 45 is lower than a preset lower limit threshold. The heating control unit 72 stops the operation of the heating unit 40 when the temperature of the carbon dioxide gas G flowing through the fifth pipe part 25 detected by the sensor 45 is higher than a preset upper limit threshold. The heating control unit 72 generates a control signal for controlling the start and stop of the heating unit 40.

[0070] The output unit 73 outputs the control signal generated by the heating control unit 72 to the heating unit 40 via the signal transceiver module 55 .

[0071] The control device 50 may also control the opening and closing of the on-off valves 21v to 25v, 25w and the operation of the compressor 30. On the other hand, the opening and closing of the on-off valves 21v to 25v, 25w and the operation and stop of the compressor 30 may be manually performed by remote operation of the operator.

[0072] (Steps of gas pressure management method)

[0073] Next, the gas pressure management method S10 in the above-mentioned ship 1 will be described.

[0074] Figure 8 Detailed description of the invention is a flowchart showing the steps of a method for managing gas pressure in a floating body according to an embodiment of the present disclosure.

[0075] like Figure 8 As shown, the gas pressure management method S10 in this embodiment includes the following steps: a step S11 of detecting the temperature of the carbon dioxide gas G; a step S12 of determining whether the temperature of the carbon dioxide gas G is below a lower limit threshold; a step S13 of heating the carbon dioxide gas G; a step S14 of determining whether the temperature of the carbon dioxide gas G is above an upper limit threshold; and a step S15 of stopping the heating of the carbon dioxide gas G.

[0076] In the step S11 of detecting the temperature of the carbon dioxide gas G, the sensor 45 detects the temperature of the carbon dioxide gas G flowing through the fifth pipe section 25 of the gas line 20 in a preset cycle, and outputs a signal of the detection value to the control device 50. The signal of the detection value output from the sensor 45 is received by the signal receiving unit 71 of the control device 50.

[0077] In step S12 of determining whether the temperature of the carbon dioxide gas G is equal to or lower than a lower limit threshold, the heating control unit 72 determines whether the temperature of the carbon dioxide gas G indicated by the detection value of the sensor 45 is equal to or lower than a preset lower limit threshold.

[0078] As a result of this determination, if the temperature of the carbon dioxide gas G is below the lower limit threshold, the process proceeds to step S13 of heating the carbon dioxide gas G. On the other hand, if the temperature of the carbon dioxide gas G is not below the lower limit threshold, the process proceeds to step S14 of determining whether the temperature of the carbon dioxide gas G is above the upper limit threshold.

[0079] In the step S13 of heating the carbon dioxide gas G, the heating control unit 72 operates the heating unit 40 . Thus, the carbon dioxide gas G flowing into the heating unit 40 from the fifth pipe unit 25 is heated and flows out to the sixth pipe unit 26 on the upstream side (in other words, the inlet side) of the compressor 30 .

[0080] In the step S14 of determining whether the temperature of the carbon dioxide gas G is equal to or higher than the upper limit threshold, it is determined whether the temperature of the carbon dioxide gas G is equal to or higher than the upper limit threshold set in advance.

[0081] If the result of this determination is that the temperature of the carbon dioxide gas G is above the upper threshold, the process proceeds to step S15 of stopping the heating of the carbon dioxide gas G. On the other hand, if the temperature of the carbon dioxide gas G is not above the upper threshold, the process returns to the above-mentioned step S11 of detecting the temperature of the carbon dioxide gas G, and the above-mentioned series of processes are repeated.

[0082] In the step S15 of stopping the heating of the carbon dioxide gas G, the operation of the heating unit 40 is stopped by the heating control unit 72. Thus, the heating of the carbon dioxide gas G by the heating unit 40 is stopped on the upstream side of the compressor 30.

[0083] (Effect)

[0084] In the ship 1 of the above-mentioned embodiment, the heating unit 40 and the compressor 30 are provided in the gas line 20. Thus, the carbon dioxide gas G passing through the gas line 20 is heated by the heating unit 40 and then compressed by the compressor 30. In this way, the temperature of the carbon dioxide gas G introduced into the compressor 30 rises, so that the generation of dry ice can be suppressed at the inlet of the compressor 30 of the gas line 20, etc.

[0085] In addition, by heating the carbon dioxide gas G by the heating unit 40, in the gas pipeline 20, at the downstream side of the heating unit 40, it is possible to use piping used under conditions of higher temperatures, such as piping of normal temperature specifications, instead of piping of low temperature specifications, as piping constituting the gas pipeline 20. Specifically, the portion downstream of the heating unit 40, the sixth pipe 26, the second pipe 22, and the third pipe 23 can be formed by piping used under conditions of higher temperatures. Thus, the cost of the gas pipeline 20 can be reduced.

[0086] In the above embodiment, the gas discharge line 20E is provided with the compressor 30 and the heating unit 40. Thus, when the carbon dioxide gas G in the tank 11 is discharged to the outside of the tank 11, the carbon dioxide gas G is heated on the upstream side of the compressor 30, and the generation of dry ice can be suppressed at the inlet of the compressor 30.

[0087] Similarly, in the above embodiment, the gas supply line 20F is provided with the compressor 30 and the heating unit 40. Thus, when the carbon dioxide gas G is discharged into the tank 11, the carbon dioxide gas G can be heated on the upstream side of the compressor 30. Therefore, the generation of dry ice can be suppressed at the inlet of the compressor 30, etc.

[0088] Furthermore, in the above-described embodiment, the gas circulation line 20R is provided with the compressor 30 and the heating unit 40. Thus, when the carbon dioxide gas G in the tank 11 is taken out of the tank 11 through the gas circulation line 20R and then circulated in the tank 11, the carbon dioxide gas G can be heated on the upstream side of the compressor 30. Therefore, the generation of dry ice can be suppressed at the inlet of the compressor 30 or the like.

[0089] Furthermore, in the above-described embodiment, the compressor 30 and the heating unit 40 are provided between the fifth pipe portion 25 and the sixth pipe portion 26 shared by the gas exhaust line 20E, the gas supply line 20F, and the gas circulation line 20R, so that the number of compressors 30 and the heating unit 40 can be reduced compared to the case where the gas exhaust line 20E, the gas supply line 20F, and the gas circulation line 20R are provided with the compressor 30 and the heating unit 40 separately. As a result, the increase in the number of components can be suppressed, and the degree of freedom of arrangement can be improved.

[0090] Furthermore, the ship 1 of the above-described embodiment includes the sensor 45 and the heating control unit 72 .

[0091] Thus, it is possible to detect the temperature of the carbon dioxide gas G at the inlet side of the compressor 30. Furthermore, when the temperature detected by the sensor 45 is equal to or lower than a preset lower limit threshold, the carbon dioxide gas G can be heated, so that the generation of dry ice can be effectively suppressed at the inlet side of the compressor 30 of the gas line 20, etc.

[0092] In addition, according to the gas pressure management method S10 of the above-described embodiment, when the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 is less than a preset lower limit threshold, the carbon dioxide gas G is heated. As a result, the temperature of the carbon dioxide gas G introduced into the compressor 30 can be increased to be higher than the lower limit threshold, so that the generation of dry ice can be effectively suppressed at the inlet side of the compressor 30 of the gas line 20, etc.

[0093] (Other Implementations)

[0094] As mentioned above, although the embodiment of this disclosure is described in detail with reference to drawings, the specific structure is not limited to this embodiment, and design changes etc. which do not deviate from the gist of this disclosure are also included.

[0095] For example, in the above-mentioned embodiment, the ship 1 is described as an example of a floating body, but a floating body such as an FSU (Floating Storage Unit) or an FSRU (Floating Storage and Regasification Unit) may be used.

[0096] Furthermore, in the above-described embodiment, when the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 is below the lower limit threshold, the carbon dioxide gas G is heated, but the present invention is not limited thereto. For example, the heating unit 40 may heat the carbon dioxide gas G all the time when the carbon dioxide gas G is compressed by the compressor 30.

[0097] In addition, in the above-mentioned embodiment, the gas line 20 is configured to have the gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R, but the present invention is not limited thereto. The gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R may be provided separately. In this case, the compressor 30 and the heating unit 40 may be provided separately for the gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R. In addition, the compressor 30 and the heating unit 40 may be provided only for a part of the gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R.

[0098] Furthermore, in the above-mentioned embodiment, when the carbon dioxide gas G is circulated in the gas line 20, the carbon dioxide gas G must pass through the heating unit 40 and the compressor 30, but the present invention is not limited thereto. For example, a bypass line that bypasses the heating unit 40 and the compressor 30 may be provided, and the carbon dioxide gas G may pass through the bypass line without being compressed by the compressor 30.

[0099] <Notes>

[0100] The floating body 1 and the gas pressure management method S10 described in the embodiment can be understood, for example, as follows.

[0101] (1) The first embodiment of the floating body 1 comprises: a floating body 2; a tank 11, which is provided on the floating body 2 and can store liquefied carbon dioxide L; a supply pipeline 15, which can supply the liquefied carbon dioxide L into the tank 11; a discharge pipeline 16, which discharges the liquefied carbon dioxide L in the tank 11 to the outside of the tank 11; a gas pipeline 20, which is connected to the tank 11 and can supply carbon dioxide gas G to flow; a compressor 30, which is provided on the gas pipeline 20; and a heating unit 40, which is provided on the upstream side of the compressor 30 in the gas pipeline 20 and can heat the carbon dioxide gas G flowing in the gas pipeline 20.

[0102] Examples of the floating body 1 include ships and offshore floating equipment. Examples of the floating body main body 2 include a ship hull and a floating body main body of an offshore floating equipment.

[0103] In the floating body 1 having such a structure, liquefied carbon dioxide L is supplied into the tank 11 through the supply line 15 . As the liquefied carbon dioxide L is supplied into the tank 11 , the carbon dioxide gas G in the tank 11 in the gas phase is pushed out of the tank 11 through the gas line 20 .

[0104] In addition, the liquid carbon dioxide in the tank 11 can be discharged to the outside of the tank 11 through the discharge line 16. As the liquid carbon dioxide in the tank 11 is discharged, the carbon dioxide gas G is introduced from the outside of the tank 11 to the inside of the tank 11 through the gas line 20.

[0105] The gas line 20 is provided with a heating unit 40 and a compressor 30. The carbon dioxide gas G passing through the gas line 20 is heated by the heating unit 40 and then compressed by the compressor 30. Thus, the temperature of the carbon dioxide gas G introduced into the compressor 30 rises, so that the generation of dry ice can be suppressed at the inlet of the compressor 30 of the gas line 20.

[0106] In addition, by heating the carbon dioxide gas G by the heating unit 40, it is possible to use normal temperature specification piping, etc., instead of low temperature specification piping, as piping constituting the gas pipeline 20 at a position downstream of the heating unit 40. Specifically, the portion downstream of the heating unit 40, the sixth pipe 26, the second pipe 22, and the third pipe 23 can be formed by normal temperature specification piping. Thus, the cost of the gas pipeline 20 can be reduced.

[0107] (2) The second embodiment of the floating body 1 is the floating body 1 of (1), wherein the gas line 20 includes a gas discharge line 20E for discharging the carbon dioxide gas G in the tank 11 to the outside of the tank 11, and the compressor 30 and the heating unit 40 are provided in the gas discharge line 20E.

[0108] Thus, when the carbon dioxide gas G in the tank 11 is discharged to the outside of the tank 11 , the carbon dioxide gas G is heated on the upstream side of the compressor 30 , thereby suppressing the generation of dry ice at the inlet of the compressor 30 .

[0109] (3) A third type of floating body 1 is based on the floating body 1 of (1) or (2), wherein the gas pipeline 20 includes a gas supply pipeline 20F for supplying the carbon dioxide gas G from outside the tank 11 to inside the tank 11, and the compressor 30 and the heating unit 40 are provided on the gas supply pipeline 20F.

[0110] Thus, when the carbon dioxide gas G is discharged into the tank 11, the carbon dioxide gas G can be heated on the upstream side of the compressor 30. Therefore, the generation of dry ice can be suppressed at the inlet of the compressor 30 and the like.

[0111] (4) A fourth embodiment of the float 1 is a float 1 according to any one of (1) to (3), wherein the gas pipeline 20 includes a gas circulation pipeline 20R for taking the carbon dioxide gas G in the tank 11 out of the tank 11 and returning it to the tank 11, and the heating unit 40 and the compressor 30 are provided in the gas circulation pipeline 20R.

[0112] Thus, when the carbon dioxide gas G in the tank 11 is taken out of the tank 11 through the gas circulation line 20R and then circulated in the tank 11, the carbon dioxide gas G can be heated on the upstream side of the compressor 30. Therefore, the generation of dry ice can be suppressed at the inlet of the compressor 30, etc.

[0113] (5) The fifth embodiment of the float 1 is based on the float 1 of any one of (1) to (4), and the float 1 comprises: a sensor 45 for detecting the temperature of the carbon dioxide gas G at the inlet side of the compressor 30; and a heating control unit 72 for heating the carbon dioxide gas G when the detected temperature is below a preset lower limit threshold.

[0114] According to such a configuration, when the temperature detected by the sensor 45 is equal to or lower than a preset lower limit threshold, the carbon dioxide gas G can be heated, so that the generation of dry ice can be effectively suppressed at the inlet side of the compressor 30 of the gas line 20 .

[0115] (6) The sixth mode of the gas pressure management method S10 is a gas pressure management method S10 in any one of the floats 1 of (1) to (5), comprising the following steps: a step S11 of detecting the temperature of the carbon dioxide gas G flowing in the gas pipeline 20; a step S12 of determining whether the detected temperature of the carbon dioxide gas G is below a preset lower limit threshold; and a step S13 of heating the carbon dioxide gas G flowing in the gas pipeline 20 by the heating unit 40 when it is determined that the temperature of the carbon dioxide gas G is below the lower limit threshold.

[0116] According to such a configuration, when the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 is lower than a preset lower limit threshold, the carbon dioxide gas G can be heated, so that the temperature of the carbon dioxide gas G introduced into the compressor 30 can be increased to be higher than the lower limit threshold. Therefore, the generation of dry ice can be effectively suppressed at the inlet side of the compressor 30 of the gas line 20, etc.

[0117] Possibility of Industrial Application

[0118] According to the floating body and the gas pressure control method disclosed in the present invention, the generation of dry ice can be suppressed.

[0119] Description of Reference Numerals

[0120] 1…Ship (floating body) 2…Hull (floating body body) 2a…Bow 2b…Stern 3A, 3B…Side 5…Upper deck 7…Upper structure 8…Cargo loading area 10…Tank equipment 11…Tank 11t…Top 12…Cylinder 13…End plate 15…Supply line 15a…Front end 16…Discharge line 16a…Front end 18…Pump 20…Gas line 20E…Gas discharge line 20F…Gas supply line 20R…Gas circulation line 21…First pipe 21a…One end 21b…Other end End 21v...opening and closing valve 22...second pipe 22a...one end 22b...other end 22v...opening and closing valve 23...third pipe 23a...one end 23b...other end 23v...opening and closing valve 24...fourth pipe 24a...one end 24b...other end 24v...opening and closing valve 25...fifth pipe 25a...one end 25b...other end 25v, 25w...opening and closing valve 30...compressor 40...heating unit 45...sensor 50...control device 51...CPU 52…ROM 53…RAM 54…memory 55…signal transceiver module 71…signal receiving unit 72…heating control unit 73…output unit Da…bow and stern direction Dv…up and down direction Dx…length direction G…carbon dioxide gas L…liquefied carbon dioxide S10…gas pressure management method S11…process for detecting the temperature of carbon dioxide gas S12…process for determining whether the temperature of carbon dioxide gas is below the lower limit threshold value S13…process for heating carbon dioxide gas S14…process for determining whether the temperature of carbon dioxide gas is above the upper limit threshold value S15…process for stopping the heating of carbon dioxide gas.

Claims

1. A floating body, comprising: floating body main body; A tank, provided on the floating body, capable of storing liquefied carbon dioxide; a supply pipeline for supplying the liquefied carbon dioxide into the tank; a discharge pipeline for discharging the liquefied carbon dioxide in the tank to the outside of the tank; a gas pipeline connected to the tank and capable of supplying carbon dioxide gas; a compressor, disposed in the gas pipeline, for compressing the carbon dioxide gas flowing in the gas pipeline; and The heating unit is provided on the upstream side of the compressor in the gas line and is capable of heating the carbon dioxide gas flowing through the gas line.

2. The floating body according to claim 1, wherein: The gas pipeline includes a gas exhaust pipeline for exhausting the carbon dioxide gas in the tank to the outside of the tank. The compressor and the heating unit are provided on the gas exhaust line.

3. The floating body according to claim 1 or 2, wherein: The gas pipeline includes a gas supply pipeline for supplying the carbon dioxide gas from outside the tank to inside the tank. The compressor and the heating unit are provided on the gas supply line.

4. The floating body according to claim 1 or 2, wherein: The gas pipeline includes a gas circulation pipeline for taking the carbon dioxide gas in the tank out of the tank and returning it to the tank. The heating unit and the compressor are provided in the gas circulation line.

5. The floating body according to claim 1 or 2, wherein: The floating body includes: a sensor for detecting a temperature of the carbon dioxide gas at an inlet side of the compressor; and The heating control unit heats the carbon dioxide gas when the detected temperature is equal to or lower than a preset lower limit threshold.

6. A gas pressure management method, which is the gas pressure management method in a floating body according to claim 1 or 2, The gas pressure management method comprises the following steps: a step of detecting the temperature of the carbon dioxide gas flowing through the gas pipeline; a step of determining whether the detected temperature of the carbon dioxide gas is below a preset lower limit threshold; and The step of heating the carbon dioxide gas flowing through the gas line by the heating unit when it is determined that the temperature of the carbon dioxide gas is equal to or lower than the lower threshold.

Images