Floating body, gas pressure management method

Abstract

To suppress formation of dry ice.SOLUTION: A floating body includes: a floating main body; a tank provided in the floating main body and capable of retaining liquefied carbon dioxide; a supply line for supplying liquefied carbon dioxide into the tank; an ejection line for ejecting the liquefied carbon dioxide in the tank to the outside of the tank; a gas line connected to the tank and capable of circulating carbon dioxide gas; a compressor provided in the gas line for compressing the carbon dioxide gas circulating in the gas line; and a heating unit provided on an upstream side of the compressor in the gas line and capable of heating the carbon dioxide gas circulating in the gas line.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a configuration of a gas treatment system that supplies liquefied gas from a storage tank of a bunkering ship to a fuel tank of a gas propulsion ship. This gas treatment system includes a bunkering line, a vapor return line, and a reliquefaction device (bunkering management unit). The bunkering line supplies the liquefied gas in the storage tank to the fuel tank. The vapor return line transmits the vapor generated in the fuel tank to the bunkering ship during bunkering via the bunkering line. The reliquefaction device reliquefies the vapor from the storage tank and returns it to adjust the internal pressure of the storage tank. In such a configuration, a compressor is provided upstream of the reliquefaction device. The compressor compresses the vapor from the storage tank and sends it into the reliquefaction device.

[0003] By the way, even in a ship equipped with a tank capable of storing liquefied carbon dioxide, a compressor may be provided. In a tank capable of storing liquefied carbon dioxide, liquefied carbon dioxide evaporates inside the tank and carbon dioxide gas is generated. The compressor compresses the generated carbon dioxide gas. In the case of such a ship, the compressor is used to manage the pressure inside the tank through which the carbon dioxide gas flows and the piping connected to the tank.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, when a compressor is installed to compress carbon dioxide gas, the carbon dioxide gas may solidify and dry ice may be formed for the following reasons. Specifically, when the compressor is operating, for example, the flow velocity of the carbon dioxide gas increases at the compressor inlet. When the flow velocity of carbon dioxide gas increases, a local decrease in the static pressure of the carbon dioxide gas occurs. When a local decrease in the static pressure of the carbon dioxide gas occurs, the likelihood of dry ice formation increases.

[0006] This disclosure was made to solve the above problems, and provides a float that can suppress the formation of dry ice, and a gas pressure management The purpose is to provide a method. [Means for solving the problem]

[0007] To solve the above problems, the floating body according to this disclosure comprises a floating body body, a tank, a supply line, a discharge line, a gas line, a compressor, and a heating unit. The tank is provided on the floating body body. The tank is capable of storing liquefied carbon dioxide. The supply line supplies the liquefied carbon dioxide into the tank. The discharge line discharges the liquefied carbon dioxide from the tank to the outside of the tank. The gas line is connected to the tank and allows carbon dioxide gas to flow through it. The compressor is provided on the gas line. The compressor compresses the carbon dioxide gas flowing through the gas line. The heating unit is provided on the upstream side of the compressor in the gas line. The heating unit is capable of heating the carbon dioxide gas flowing through the gas line. The heating unit includes a sensor that detects the temperature of the carbon dioxide gas at the inlet side of the compressor, and a heating control unit that heats the carbon dioxide gas when the detected temperature is below a predetermined lower threshold.

[0008] Gas pressure related to this disclosure management The method is, The system comprises a floating body, a tank provided in the floating body capable of storing liquefied carbon dioxide, a supply line for supplying the liquefied carbon dioxide into the tank, a discharge line for discharging the liquefied carbon dioxide from the tank to the outside of the tank, a gas line connected to the tank through which carbon dioxide gas can flow, a compressor provided in the gas line for compressing the carbon dioxide gas flowing through the gas line, and a heating unit provided upstream of the compressor in the gas line for heating the carbon dioxide gas flowing through the gas line.A method for managing gas pressure in a floating body, comprising the steps of: detecting the temperature of carbon dioxide gas; determining whether the temperature of the carbon dioxide gas is below a predetermined lower threshold; and 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 through the gas line is detected. In the step of determining whether the temperature of the carbon dioxide gas is below a predetermined lower threshold, it is determined whether the detected temperature of the carbon dioxide gas is below a predetermined lower threshold. In the step of heating the carbon dioxide gas, if it is determined that the temperature of the carbon dioxide gas is below the lower threshold, the gas is heated and flows through the gas line. [Effects of the Invention]

[0009] Floating body, gas pressure of the present disclosure management Depending on the method, the formation of dry ice can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view showing a schematic configuration of a floating body according to the embodiment of this disclosure. [Figure 2] This is a side cross-sectional view showing a tank and a gas line provided on a floating body according to an embodiment of the present disclosure. [Figure 3] This figure shows the flow of carbon dioxide gas when carbon dioxide gas is supplied into a tank in a floating body according to an embodiment of the present disclosure. [Figure 4] This figure shows the flow of carbon dioxide gas when carbon dioxide gas is discharged outside the tank in a floating body according to an embodiment of the present disclosure. [Figure 5] This figure shows the flow of carbon dioxide gas when circulating carbon dioxide gas in a tank in a floating body according to an embodiment of the present disclosure. [Figure 6] This figure shows the hardware configuration of a control device provided on a floating body according to an embodiment of this disclosure. [Figure 7] This is a functional block diagram of a control device provided on a floating body according to an embodiment of this disclosure. [Figure 8] It is a flowchart showing the procedure of the gas pressure management method in the floating body according to an embodiment of the present disclosure.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the floating body and gas pressure according to the embodiments of the present disclosure management The method will be described with reference to FIGS. 1 to 8. (Configuration of the ship) FIG. 1 is a plan view showing a schematic configuration of a floating body according to an embodiment of the present disclosure. In an embodiment of the present disclosure, a ship (floating body) 1 that is a floating body transports liquefied carbon dioxide. As shown in FIG. 1, this ship 1 includes at least a hull 2 as a floating body main body and tank facilities 10.

[0012] (Configuration of the hull) The hull 2 has a pair of side plates 3A and 3B forming its outer shell, a bottom (not shown), and an upper deck 5. The side plates 3A and 3B have a pair of side outer plates forming the left and right sides respectively. The bottom (not shown) has a bottom outer plate connecting these side plates 3A and 3B. By these pair of side plates 3A and 3B and the bottom (not shown), the outer shell of the hull 2 forms a U shape in a cross section perpendicular to the bow-stern direction Da. The upper deck 5 illustrated in this embodiment is an all-through deck exposed to the outside. An upper structure 7 having a living area is formed on the upper deck 5 on the stern 2b side of the hull 2, for example. Note that the position and size of the upper structure 7 can be changed as appropriate.

[0013] Inside the hull 2, a cargo loading compartment (hold) 8 is formed on the bow 2a side of the upper structure 7. The cargo loading compartment 8 is recessed downward from the upper deck 5 toward the bottom and is open upward.

[0014] (Configuration of the tank facilities) A plurality of tank facilities 10 are arranged side by side in the bow-stern direction Da within the cargo loading compartment 8. In an embodiment of the present disclosure, for example, two tank facilities 10 are arranged at intervals in the bow-stern direction Da.

[0015] Figure 2 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. As shown in FIG. 2, 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. In this embodiment, the tank 11 is disposed in the hull 2 and has, for example, a cylindrical shape extending in the fore-and-aft direction Da. The tank 11 can store liquefied carbon dioxide L therein. The tank 11 includes a cylindrical portion 12 and a mirror plate portion 13. The cylindrical portion 12 extends with the fore-and-aft direction Da as the longitudinal direction Dx. In this embodiment, the cylindrical portion 12 is formed in a cylindrical shape, and the cross-sectional shape perpendicular to the longitudinal direction Dx thereof is circular. The mirror plate portions 13 are respectively disposed at both ends in the longitudinal direction Dx of the cylindrical portion 12. Each mirror plate portion 13 is hemispherical and closes the openings at both ends in the longitudinal direction Dx of the cylindrical portion 12. Note that the tank 11 is not limited to a cylindrical shape and may have other shapes such as a spherical shape or a square shape.

[0016] The supply line 15 loads the liquefied carbon dioxide L supplied from outside the ship, such as a land-based liquefied carbon dioxide supply facility or another ship storing liquefied carbon dioxide, into the tank 11. The supply line 15 penetrates the top of the tank 11 from the outside of the tank 11 and reaches the lower part of the tank 11. The tip 15a (in other words, the lower end in the vertical direction Dv) of the supply line 15 opens downward at the lower part inside the tank 11.

[0017] The discharge line 16 discharges the liquefied carbon dioxide L in the tank 11 to the outside of the ship, such as a land-based liquefied carbon dioxide storage facility. The tip 16a of the discharge line 16 is connected to a pump 18 disposed at the lower part inside the tank 11. The discharge line 16 extends upward from the tip 16a, penetrates the top of the tank 11, and reaches the outside of the tank 11. The pump 18 connected to the tip 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.

[0018] The gas line 20 is designed to allow at least the carbon dioxide gas G in tank 11 to flow through it. The carbon dioxide gas G in tank 11 is below 0°C and above the triple point temperature of carbon dioxide. The carbon dioxide gas G in tank 11 is mainly so-called boil-off gas, which is the evaporation of liquefied carbon dioxide L stored in tank 11, and is, for example, between -56°C and -10°C.

[0019] The gas line 20 comprises a first pipe section 21, a second pipe section 22, a third pipe section 23, a fourth pipe section 24, a fifth pipe section 25, and a sixth pipe section 26.

[0020] The first pipe section 21 is used to send carbon dioxide gas G supplied from outside the ship into the tank 11. One end 21a of the first pipe section 21 is configured to allow connection of 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 boil-off gas described above. The other end 21b of the first pipe section 21 is connected to one end 25a of the fifth pipe section 25, which will be described later. The first pipe section 21 is provided with an on / off valve 21v.

[0021] The second pipe section 22 is used to discharge carbon dioxide gas G from the tank 11 overboard. One end 22a of the second pipe section 22 is configured to allow connection of a discharge pipe (not shown) for discharging 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, which will be described later. The second pipe section 22 is provided with an on / off valve 22v.

[0022] The third pipe section 23 is used to supply carbon dioxide gas G 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, which will be described later. The third pipe section 23 is equipped with an on / off valve 23v.

[0023] The fourth pipe section 24 is used to discharge carbon dioxide gas G from the tank 11 to the outside of the tank 11. One end 24a of the fourth pipe section 24 is connected to the top 11t of the tank 11. The other end 24b of the fourth pipe section 24 is connected to one end 25a of the fifth pipe section 25, which will be described later. The fourth pipe section 24 is provided with an on / off valve 24v.

[0024] The fifth pipe section 25 is provided between the other end 21b of the first pipe section 21 and 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. The fifth pipe section 25 is provided with an on-off valve 25v. The on-off valve 25v is provided on the upstream side in the direction of carbon dioxide gas flow relative to the heating section 40, which will be described later.

[0025] The sixth pipe section 26 is located between the heating section 40 and the other end 22b of the second pipe section 22 and the other end 23b of the third pipe section 23. One end 26a of the sixth pipe section 26 is connected to the outlet of the heating section 40. The other end 26b of the sixth pipe section 26 is connected to the other end 22b of the second pipe section 22 and the other end 23b of the third pipe section 23. A compressor 30 and an on-off valve 25w are provided in the middle of the sixth pipe section 26. The on-off valve 25w is located on the other end 26b side of the compressor 30.

[0026] The compressor 30 compresses the carbon dioxide gas G that flows in through the fifth pipe section 25 and the sixth pipe section 26. The compressor 30 compresses the carbon dioxide gas G drawn in from the inlet side and discharges it to the other end 26b side of the sixth pipe section 26. Therefore, the carbon dioxide gas G flows through the sixth pipe section 26 from one end 26a to the other end 26b.

[0027] The heating unit 40 is located between the fifth pipe section 25 and the sixth pipe section 26. In other words, the heating unit 40 is located upstream of the compressor 30. The heating unit 40 heats the carbon dioxide gas G flowing through the fifth pipe section 25. For example, a heat exchanger can be used as the heating unit 40. The heating unit 40 heats the carbon dioxide gas G flowing through the fifth pipe section 25. For example, the heating unit 40 may heat the carbon dioxide gas G flowing through the fifth pipe section 25 from -56°C to -10°C to a temperature higher than -10°C and below the upper limit temperature of the design conditions (for example, around 80°C).

[0028] A sensor 45 is provided in the fifth pipe section 25. The sensor 45 detects the temperature of the carbon dioxide gas G flowing through the fifth pipe section 25. The sensor 45 outputs a signal of the detected temperature to the control device 50.

[0029] (Operation of gas lines) The gas line 20 described above has functional configurations as a gas supply line 20F, a gas discharge line 20E, and a gas circulation line 20R. By switching the on / off valves 21v~25v and 25w of the gas line 20, it is possible to selectively select and use one of the gas supply line 20F, gas discharge line 20E, or gas circulation line 20R.

[0030] Figure 3 shows the flow of carbon dioxide gas when carbon dioxide gas is supplied into a tank in a floating body according to an embodiment of this disclosure. As shown in Figure 3, the gas supply line 20F is configured by closing the on-off valves 22v and 24v and opening the on-off valves 21v, 25v, 25w, and 23v. The gas supply line 20F is used when supplying carbon dioxide gas G from outside the tank 11 into the tank 11. In this case, the carbon dioxide gas G supplied from outside the tank 11 is supplied into 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. In other words, the gas supply line 20F is composed of the first pipe section 21, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23.

[0031] The gas supply line 20F is used, for example, to cool the inside of the tank 11 and to increase the pressure inside the tank 11 before supplying liquefied carbon dioxide L to the tank 11. Furthermore, the gas supply line 20F is used, for example, to prevent a decrease in pressure inside the tank 11 when liquefied carbon dioxide L is discharged from the tank 11 through the discharge line 16, as the amount of liquefied carbon dioxide L inside the tank decreases. Note that the usage of the gas supply line 20F may be other than those described above.

[0032] When carbon dioxide gas G is supplied into the tank 11 through the gas supply line 20F, the compressor 30 is activated to compress the carbon dioxide gas G being sent into the tank 11. This allows the pressure of the gas phase inside the tank 11 to be increased to a preset target pressure.

[0033] Figure 4 shows the flow of carbon dioxide gas when carbon dioxide gas is discharged outside the tank in a floating body according to an embodiment of this disclosure. As shown in Figure 4, the gas discharge line 20E is configured by closing the on-off valves 21v and 23v, and opening the on-off valves 24v, 25v, 25w, and 22v. The gas discharge line 20E is used when discharging carbon dioxide gas G from inside the tank 11 to outside the tank 11. In this case, the carbon dioxide gas G inside the tank 11 is discharged outside the tank 11 via the fourth pipe section 24, the fifth pipe section 25, the sixth pipe section 26, and the second pipe section 22. In other words, the gas discharge line 20E is composed of the fourth pipe section 24, the fifth pipe section 25, the sixth pipe section 26, and the second pipe section 22.

[0034] The gas discharge line 20E is used, for example, when supplying liquefied carbon dioxide L into the tank 11 through the supply line 15, to suppress the increase in pressure inside the tank 11 as the amount of liquefied carbon dioxide L inside the tank increases. Note that the gas discharge line 20E may be used in ways other than those described above.

[0035] When carbon dioxide gas G is discharged outside the tank 11 through the gas discharge line 20E, the compressor 30 is activated, compressing the carbon dioxide gas G being discharged outside the tank 11. This allows for efficient discharge of carbon dioxide gas G. Therefore, the pressure of the gas phase inside the tank 11 can be efficiently managed to match a preset target pressure.

[0036] Figure 5 shows the flow of carbon dioxide gas when the carbon dioxide gas in the tank is circulated in a floating body according to the embodiment of this disclosure. As shown in Figure 5, the gas circulation line 20R is configured by closing the on-off valves 21v and 22v, and opening the on-off valves 24v, 25v, 25w, and 23v. In this case, the carbon dioxide gas G in the tank 11 is circulated 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. In other words, the gas circulation line 20R is composed of the fourth pipe section 24, the fifth pipe section 25, the sixth pipe section 26, and the third pipe section 23.

[0037] The gas circulation line 20R is used to pressurize the carbon dioxide gas G inside the tank 11. In this case, by operating the compressor 30, the carbon dioxide gas G that has been taken out of the tank 11 and sent to the gas circulation line 20R outside the tank 11 is compressed. This increases the pressure of the carbon dioxide gas G. By returning the pressurized carbon dioxide gas G back into the tank 11, the pressure of the gas phase inside the tank 11 increases. Therefore, the pressure of the gas phase inside the tank 11 can be efficiently managed to match a preset target pressure. Note that the usage of the gas circulation line 20R may be other than that described above. In addition, in this embodiment, a reliquefaction device (not shown) for reliquefying the carbon dioxide gas G (so-called boil-off gas) generated by evaporation inside the tank 11 is provided independently of the gas line 20.

[0038] As described above, when the gas line 20 is used as a gas supply line 20F, a gas discharge line 20E, and a gas circulation line 20R, the carbon dioxide gas G flowing through the fifth pipe section 25 can be heated by the heating section 40 upstream of the compressor 30. Heating of the carbon dioxide gas G by the heating section 40 may be performed continuously, but in this embodiment, heating by the heating section 40 is performed according to the temperature of the carbon dioxide gas G upstream of the compressor 30. The operation of the heating section 40 is controlled by the control device 50.

[0039] (Hardware configuration diagram) Figure 6 shows the hardware configuration of a control device provided on a floating body according to the embodiment of this disclosure. As shown in Figure 6, the control device 50 is a computer equipped with a CPU 51 (Central Processing Unit), ROM 52 (Read Only Memory), RAM 53 (Random Access Memory), storage 54 such as an HDD (Hard Disk Drive), and a signal transmission / reception module 55. The signal transmission / reception module 55 receives signals of detected values ​​from the sensor 45.

[0040] (Functional block diagram) Figure 7 is a functional block diagram of a control device provided on a floating body according to an embodiment of this disclosure. As shown in Figure 7, 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 having the CPU 51 execute a program stored in the storage 54 such as an HDD. The signal receiving unit 71 receives a signal of the detected value from the sensor 45 via the signal transmitting / receiving module 55.

[0041] The heating control unit 72 controls the operation of the heating unit 40 based on the value detected by the sensor 45. The heating control unit 72 controls the operation and stopping of the heating unit 40. The heating control unit 72 activates the heating unit 40 when the temperature of the carbon dioxide gas G flowing through the fifth pipe section 25, as detected by the sensor 45, is lower than a predetermined lower 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 section 25, as detected by the sensor 45, is higher than a predetermined upper threshold. The heating control unit 72 generates control signals to control the starting and stopping of the heating unit 40. The output unit 73 outputs the control signal generated by the heating control unit 72 to the heating unit 40 via the signal transmission / reception module 55.

[0042] Furthermore, the control device 50 may also control the opening and closing of the on-off valves 21V~25V and 25W, and the operation of the compressor 30. On the other hand, the opening and closing of the on-off valves 21V~25V and 25W, and the operation and stopping of the compressor 30 may be performed manually by an operator via remote control or the like.

[0043] (Procedure for managing gas pressure) Next, we will explain the gas pressure management method S10 in the vessel 1 described above. Figure 8 is a flowchart showing the procedure for a gas pressure management method in a floating body according to an embodiment of this disclosure. As shown in Figure 8, the gas pressure management method S10 in this embodiment includes a step S11 for detecting the temperature of carbon dioxide gas G, a step S12 for determining whether the temperature of carbon dioxide gas G is below a lower threshold, a step S13 for heating carbon dioxide gas G, a step S14 for determining whether the temperature of carbon dioxide gas G is above an upper threshold, and a step S15 for stopping the heating of carbon dioxide gas G.

[0044] In step S11, which detects the temperature of carbon dioxide gas G, the sensor 45 detects the temperature of 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 detected value to the control device 50. This signal of the detected value output from the sensor 45 is received by the signal receiving unit 71 of the control device 50.

[0045] In step S12, which determines whether the temperature of carbon dioxide gas G is below a lower threshold, the heating control unit 72 determines whether the temperature of carbon dioxide gas G, as indicated by the value detected by the sensor 45, is below a predetermined lower threshold. If the result of this determination is that the temperature of carbon dioxide gas G is below the lower threshold, the process proceeds to step S13, which involves heating carbon dioxide gas G. On the other hand, if the temperature of carbon dioxide gas G is not below the lower threshold, the process proceeds to step S14, which involves determining whether the temperature of carbon dioxide gas G is above the upper threshold.

[0046] In step S13, which involves heating carbon dioxide gas G, the heating control unit 72 activates the heating unit 40. As a result, the carbon dioxide gas G that flows into the heating unit 40 from the fifth pipe section 25 is heated and flows out into the sixth pipe section 26, which is upstream (in other words, inlet) of the compressor 30.

[0047] In step S14, which determines whether the temperature of carbon dioxide gas G is above an upper threshold, it is determined whether the temperature of carbon dioxide gas G is above a predetermined upper threshold. If the result of this determination shows that the temperature of carbon dioxide gas G is above the upper threshold, the process proceeds to step S15, where the heating of carbon dioxide gas G is stopped. On the other hand, if the temperature of carbon dioxide gas G is not above the upper threshold, the process returns to step S11, where the temperature of carbon dioxide gas G is detected, and the series of processes described above are repeated.

[0048] In step S15, which involves stopping the heating of carbon dioxide gas G, the heating control unit 72 stops the operation of the heating unit 40. As a result, the heating of carbon dioxide gas G by the heating unit 40 is stopped upstream of the compressor 30.

[0049] (Effects and Benefits) In the vessel 1 of the above embodiment, a heating unit 40 and a compressor 30 are provided in the gas line 20. As a result, the carbon dioxide gas G passing through the gas line 20 is heated in the heating unit 40 and then compressed in the compressor 30. In this way, the temperature of the carbon dioxide gas G introduced into the compressor 30 is raised, so the formation of dry ice can be suppressed at the inlet of the compressor 30 in the gas line 20. Furthermore, by heating carbon dioxide gas G in the heating section 40, in the gas line 20, downstream of the heating section 40, the piping constituting the gas line 20 can be made from piping designed for higher temperatures, such as room temperature piping, rather than piping designed for low temperatures. Specifically, the downstream sections of the heating section 40, the sixth pipe section 26, the second pipe section 22, and the third pipe section 23, can be made from piping designed for higher temperatures. This makes it possible to reduce the cost of the gas line 20.

[0050] In the above embodiment, a compressor 30 and a heating unit 40 are provided in the gas discharge line 20E. This allows for the suppression of dry ice formation at the inlet of the compressor 30, etc., by heating the carbon dioxide gas G upstream of the compressor 30 when discharging the carbon dioxide gas G from the tank 11 to the outside of the tank 11.

[0051] Similarly, in the above embodiment, a compressor 30 and a heating unit 40 are provided in the gas supply line 20F. This allows the carbon dioxide gas G to be heated upstream of the compressor 30 when it is discharged into the tank 11. Therefore, the formation of dry ice can be suppressed at the inlet of the compressor 30, etc.

[0052] Furthermore, in the above embodiment, a compressor 30 and a heating unit 40 are provided in the gas circulation line 20R. This allows the carbon dioxide gas G in the tank 11 to be heated upstream of the compressor 30 when it is taken out of the tank 11 through the gas circulation line 20R and then circulated back into the tank 11. Therefore, the formation of dry ice at the inlet of the compressor 30 can be suppressed.

[0053] In the above embodiment, since the compressor 30 and heating unit 40 are provided between the fifth pipe section 25 and the sixth pipe section 26, which are shared by the gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R, the number of compressors 30 and heating units 40 can be reduced compared to the case where the compressor 30 and heating unit 40 are individually provided in the gas discharge line 20E, the gas supply line 20F, and the gas circulation line 20R. As a result, the increase in the number of parts can be suppressed and the degree of freedom in arrangement can be improved.

[0054] Furthermore, the vessel 1 in the above embodiment is equipped with a sensor 45 and a heating control unit 72. This allows the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 to be detected. When the temperature detected by the sensor 45 is below a predetermined lower threshold, the carbon dioxide gas G can be heated, thereby effectively suppressing the formation of dry ice at the inlet side of the compressor 30 in the gas line 20.

[0055] Furthermore, according to the gas pressure management method S10 of the above embodiment, the carbon dioxide gas G is heated when the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 is below a predetermined lower threshold. This makes it possible to raise the temperature of the carbon dioxide gas G introduced into the compressor 30 above the lower threshold, thereby effectively suppressing the formation of dry ice at the inlet side of the compressor 30 in the gas line 20.

[0056] (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. For example, in the embodiment described above, a ship 1 was used as an example of a floating body, but other floating bodies such as an FSU (Floating Storage Unit) or an FSRU (Floating Storage and Regasification Unit) may also be used.

[0057] Furthermore, in the above embodiment, the carbon dioxide gas G is heated when the temperature of the carbon dioxide gas G at the inlet side of the compressor 30 is below a lower threshold, but the embodiment is not limited to this. For example, the heating of the carbon dioxide gas G by the heating unit 40 may be performed continuously when the carbon dioxide gas G is compressed by the compressor 30.

[0058] Furthermore, in the above embodiment, the gas line 20 is configured to serve as both a gas discharge line 20E, a gas supply line 20F, and a gas circulation line 20R, but the invention is not limited to this configuration. The gas discharge line 20E, gas supply line 20F, and gas circulation line 20R may each be provided individually. In that case, the compressor 30 and the heating unit 40 may be provided in each of the gas discharge line 20E, gas supply line 20F, and gas circulation line 20R. Alternatively, the compressor 30 and the heating unit 40 may be provided in only a portion of the gas discharge line 20E, gas supply line 20F, and gas circulation line 20R.

[0059] Furthermore, in the above embodiment, when carbon dioxide gas G is circulated in the gas line 20, the carbon dioxide gas G is always configured to pass through the heating unit 40 and the compressor 30, but this is not limited to this configuration. For example, a bypass line may be provided that bypasses the heating unit 40 and the compressor 30, so that when the carbon dioxide gas G is not compressed by the compressor 30, the carbon dioxide gas G is passed through the bypass line.

[0060] <Note> The floating body 1 and gas pressure management method S10 described in the embodiment can be understood, for example, as follows.

[0061] (1) The floating body 1 according to the first embodiment comprises a floating body body 2, a tank 11 provided in the floating body body 2 and capable of storing liquefied carbon dioxide L, a supply line 15 capable of supplying the liquefied carbon dioxide L into the tank 11, a discharge line 16 for discharging the liquefied carbon dioxide L from the tank 11 to the outside of the tank 11, a gas line 20 connected to the tank 11 through which carbon dioxide gas G can flow, a compressor 30 provided in the gas line 20, and a heating unit 40 provided upstream of the compressor 30 in the gas line 20 and capable of heating the carbon dioxide gas G flowing through the gas line 20. Examples of floating structure 1 include ships and offshore floating facilities. Examples of floating structure body 2 include ship hulls and the floating body of offshore floating facilities.

[0062] In this configuration, liquefied carbon dioxide L is supplied into the tank 11 through the supply line 15. As liquefied carbon dioxide L is supplied into the tank 11, the carbon dioxide gas G that forms the gas phase inside the tank 11 is pushed out to the outside of the tank 11 through the gas line 20. Furthermore, the liquid carbon dioxide in tank 11 can be discharged outside tank 11 through the discharge line 16. As the liquid carbon dioxide in tank 11 is discharged, carbon dioxide gas G is introduced into tank 11 from outside through the gas line 20. The gas line 20 is equipped with a heating unit 40 and a compressor 30. The carbon dioxide gas G passing through the gas line 20 is heated in the heating unit 40 and then compressed in the compressor 30. In this way, the temperature of the carbon dioxide gas G introduced into the compressor 30 is increased, which helps to suppress the formation of dry ice at the inlet of the compressor 30 in the gas line 20. Furthermore, by heating carbon dioxide gas G in the heating section 40, downstream of the heating section 40 of the gas line 20, the piping constituting the gas line 20 can be made of room temperature piping instead of low temperature piping. Specifically, the downstream sections of the heating section 40, the sixth pipe section 26, the second pipe section 22, and the third pipe section 23, can be formed using room temperature piping. This makes it possible to reduce the cost of the gas line 20.

[0063] (2) The floating body 1 according to the second embodiment 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.

[0064] As a result, 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 upstream of the compressor 30, thereby suppressing the formation of dry ice at the inlet of the compressor 30, etc.

[0065] (3) The floating body 1 according to the third embodiment is the floating body 1 of (1) or (2), wherein the gas line 20 includes a gas supply line 20F that supplies the carbon dioxide gas G from outside the tank 11 into the tank 11, and the compressor 30 and the heating unit 40 are provided in the gas supply line 20F.

[0066] This allows the carbon dioxide gas G to be heated upstream of the compressor 30 when it is discharged into the tank 11. Therefore, the formation of dry ice at the inlet of the compressor 30 can be suppressed.

[0067] (4) The floating body 1 according to the fourth embodiment is any one of the floating bodies 1 of (1) to (3), wherein the gas line 20 includes a gas circulation line 20R that takes the carbon dioxide gas G from the tank 11 out of the tank 11 and returns it to the tank 11, and the heating unit 40 and the compressor 30 are provided in the gas circulation line 20R.

[0068] This allows the carbon dioxide gas G in tank 11 to be heated upstream of the compressor 30 when it is taken out of tank 11 through the gas circulation line 20R and then circulated back into tank 11. Therefore, the formation of dry ice at the inlet of the compressor 30 can be suppressed.

[0069] (5) The floating body 1 according to the fifth embodiment is any one of the floating bodies 1 from (1) to (4), and comprises a sensor 45 for detecting the temperature of the carbon dioxide gas G on 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 predetermined lower threshold.

[0070] With this configuration, the carbon dioxide gas G can be heated when the temperature detected by the sensor 45 is below a predetermined lower threshold, thereby effectively suppressing the formation of dry ice at the inlet side of the compressor 30 in the gas line 20.

[0071] (6) A gas pressure management method S10 according to the sixth embodiment is a gas pressure management method S10 in any one of the floating bodies 1 according to (1) to (5), comprising: a step S11 for detecting the temperature of carbon dioxide gas G flowing through the gas line 20; a step S12 for determining whether the detected temperature of the carbon dioxide gas G is below a predetermined lower threshold; and a step S13 for heating the carbon dioxide gas G flowing through the gas line 20 with the heating unit 40 if it is determined that the temperature of the carbon dioxide gas G is below the lower threshold.

[0072] With this configuration, the carbon dioxide gas G can be heated when its temperature at the inlet side of the compressor 30 is below a predetermined lower threshold, thereby raising the temperature of the carbon dioxide gas G introduced into the compressor 30 above the lower threshold. Therefore, the formation of dry ice can be effectively suppressed at the inlet side of the compressor 30 in the gas line 20. [Explanation of Symbols]

[0073] 1...Ship (floating hull) 2...Hull (main body of the floating hull) 2a...Bow 2b...Stern 3A, 3B...Side 5...Upper deck 7...Superstructure 8...Cargo loading compartment 10...Tank equipment 11...Tank 11t...Top 12...Cylindrical section 13...End plate section 15...Supply line 15a...Tip 16...Discharge line 16a...Tip 18...Pump 20...Gas line 20E...Gas discharge line 20F...Gas supply line 20R...Gas circulation line 21...First pipe section 21a...One end 21b...Other end 21v...On-off valve 22...Second pipe section 22a...One end 22b...Other end 22v...On-off valve 23...Third pipe section 23a...One end 23b...Other end 23v...On-off valve 24...Fourth pipe section 24a...One end 24b...Other end 24v...On / off valve 25...Fifth pipe section 25a...One end 25b...Other end 25v, 25w...On / off valve 30...Compressor 40...Heating unit 45...Sensor 50...Control device 51...CPU 52...ROM 53...RAM 54...Storage 55...Signal transmission / reception module 71...Signal reception unit 72...Heating control unit 73...Output unit Da...Bow / stern direction Dv...Up / down direction Dx...Longitudinal direction G...Carbon dioxide gas L...Liquefied carbon dioxide S10...Gas pressure management method S11...Step to detect the temperature of carbon dioxide gas S12...Step to determine whether the temperature of carbon dioxide gas is below the lower threshold S13...Step to heat carbon dioxide gas S14...Step to determine whether the temperature of carbon dioxide gas is above the upper threshold S15...Step to stop heating carbon dioxide gas

Claims

1. The floating body and A tank capable of storing liquefied carbon dioxide is provided on the floating body, A supply line for supplying the liquefied carbon dioxide into the tank, A discharge line for discharging the liquefied carbon dioxide in the tank to the outside of the tank, A gas line connected to the aforementioned tank through which carbon dioxide gas can flow, A compressor is provided in the gas line for compressing the carbon dioxide gas flowing through the gas line, A heating unit is provided upstream of the compressor in the gas line and capable of heating the carbon dioxide gas flowing through the gas line, A sensor for detecting the temperature of the carbon dioxide gas at the inlet side of the compressor, A heating control unit that heats the carbon dioxide gas when the detected temperature is below a predetermined lower threshold, A floating body equipped with [the following features].

2. The gas line includes a gas discharge line that discharges the carbon dioxide gas in the tank to the outside of the tank. The compressor and the heating unit are provided in the gas discharge line. The floating body according to claim 1.

3. The gas line includes a gas supply line that supplies carbon dioxide gas from outside the tank into the tank. The compressor and the heating unit are provided in the gas supply line. The floating body according to claim 1 or 2.

4. The gas line includes a gas circulation line that takes the carbon dioxide gas from the tank out of the tank and returns it to the tank. The heating unit and the compressor are provided in the gas circulation line. The floating body according to claim 1 or 2.

5. A floating body and, A tank capable of storing liquefied carbon dioxide is provided on the floating body, A supply line for supplying the liquefied carbon dioxide into the tank, A discharge line for discharging the liquefied carbon dioxide in the tank to the outside of the tank, A gas line connected to the aforementioned tank through which carbon dioxide gas can flow, A compressor is provided in the gas line for compressing the carbon dioxide gas flowing through the gas line, A gas pressure management method for a floating body, comprising: a heating unit provided upstream of the compressor in the gas line and capable of heating the carbon dioxide gas flowing through the gas line, A step of detecting the temperature of carbon dioxide gas flowing through the gas line, A step of determining whether the temperature of the detected carbon dioxide gas is below a predetermined lower threshold, If it is determined that the temperature of the carbon dioxide gas is below the lower threshold, the heating unit heats the carbon dioxide gas flowing through the gas line, the step includes: Gas pressure management methods.

Images