Liquefied gas filling system and liquefied gas filling method

Abstract

To provide a liquefied gas filling system capable of suppressing an occurrence of a water hammer phenomenon even in the case where a large-sized tank is filled with liquefied gas.SOLUTION: A liquefied gas filing system 1 includes: a storage rank 2 for storing liquefied gas; a filling tank 3 for filling liquefied gas; a supply line 4 connected to the storage tank 2 and the filling tank 3 for supplying liquefied gas from the storage tank 2 to the filling tank 3; one or two or more bypass lines 5 connected to the supply line 4; and a compressor 6 provided to the supply line 4 and the one or two or more bypass lines 5 respectively. One end of the one or two or more bypass lines 5 is connected to an entrance side of the compressor 6 provided in the supply line 4 in the supply line 4, and the other end is connected to end exit side of the compressor 6 provided in the supply line 4. A maximum filling amount of the liquefied gas from the storage tank 2 to the filling tank 3 is 100 tons / hr or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquefied gas filling system and a liquefied gas filling method. [Background technology]

[0002] Liquefied gases such as liquefied carbon dioxide and liquefied petroleum gas have traditionally been filled from tank to tank. For example, filling a liquefied gas from a tank truck to a tank that is being filled with liquefied gas is performed. During this type of filling, a compressor is typically operated at high speed from the start of filling to fill the liquefied gas into the tank, and an operator checks the amount of filling with a measuring meter. When the predetermined amount is reached, the operator manually stops the compressor to complete filling of the liquefied gas into the tank.

[0003] For example, Patent Document 1 discloses a liquefied petroleum gas filling device that includes a liquid transfer line that connects the liquid phase of a lorry tank and the gas phase of a bulk container via a pump, and a gas phase line that connects the lorry tank and the gas phase of the bulk container.

[0004] Furthermore, when filling a tank with liquefied gas, the flow rate of the liquefied gas is adjusted by controlling a valve. For example, Patent Document 2 discloses a liquefied gas filling system comprising: a liquefied gas filling path having one end connected to a liquid phase region of a liquefied gas storage tank and the other end connected to a liquid phase region of a fuel tank; a gas phase region pressure equalization path having one end connected to a gas phase region of the liquefied gas storage tank and the other end connected to the gas phase region of the fuel tank; a pressurizing means for supplying the liquefied gas in the liquefied gas storage tank to the fuel tank by pressurizing the liquefied gas; a filling on-off valve arranged in the liquefied gas filling path; a pressure equalization on-off valve arranged in the gas phase region pressure equalization path; a receiving means for receiving liquid level detection data transmitted by the transmitting means; a filling start operating unit that is operated when starting to fill the fuel tank with liquefied gas from the liquefied gas storage tank; and a control means for controlling the amount of liquefied gas filled into the fuel tank. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-291889 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-255809 Summary of the Invention [Problem to be solved by the invention]

[0006] Recently, there has been an increasing need for the mass transportation of liquefied gases such as liquefied carbon dioxide. In such mass transportation of liquefied gases, the liquefied gas is filled into large tanks such as cargo tanks of large transport ships.

[0007] When filling a large tank like the one described above with liquefied gas, unlike filling a relatively small amount of liquefied gas from a tank truck into a storage tank, the amount of liquefied gas being filled into the tank is large, which takes time, and therefore requires automatic confirmation of the amount of liquefaction. Furthermore, when filling a large tank like the one described above with liquefied gas, the flow rate of the liquefied gas during filling is large and the flow rate fluctuates greatly. Therefore, if a method used when filling a relatively small amount of liquefied gas is used, the water hammer phenomenon may occur, and the resulting impact can be significant. Patent Document 2, mentioned above, measures the amount of liquefied gas filled into the tank and controls the opening and closing of a valve to control the filling flow rate, thereby reducing the impact of the water hammer phenomenon. However, this technology requires many valves and measuring instruments, which can be costly, and therefore other methods for suppressing the water hammer phenomenon are desired.

[0008] Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology and to provide a liquefied gas filling system and a liquefied gas filling method that can suppress the occurrence of the water hammer phenomenon even when filling a large tank with liquefied gas. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the inventors discovered that the filling amount can be adjusted by providing one or more bypass lines in the supply line and providing compressors in each of the supply line and the bypass line, thereby suppressing the water hammer phenomenon and enabling large amounts of liquefied gas to be filled efficiently, and thus completed the present invention. The gist of the liquefied gas filling system and liquefied gas filling method of the present invention, which solve the above problems, is as follows.

[0010] [1] A storage tank for storing liquefied gas; a filling tank for filling the liquefied gas; a supply line connected to the storage tank and the filling tank for supplying liquefied gas from the storage tank to the filling tank; one or more bypass lines connected to the supply line; a compressor provided in each of the supply line and the one or more bypass lines, one end of the one or more bypass lines is connected to an inlet side of the compressor provided in the supply line, and the other end is connected to an outlet side of the compressor provided in the supply line, A liquefied gas filling system in which the maximum filling rate of liquefied gas from the storage tank to the filling tank is 100 tons / hr or more.

[0011] [2] A liquefied gas filling system as described in [1], which has a fluid density measuring means in the supply line between the connection between the supply line and the bypass line on the outlet side of the compressor provided in the supply line and the filling tank.

[0012] [3] A liquefied gas filling system according to [1] or [2], wherein the filling tank has a liquid volume measuring means for measuring the liquid volume of the filled liquefied gas.

[0013] [4] A liquefied gas filling system according to any one of [1] to [3], having a pressure equalization line connected to the storage tank and the filling tank to equalize the pressure between the storage tank and the filling tank.

[0014] [5] A method for filling a liquefied gas, in which liquefied gas is filled from a storage tank into a filling tank through a supply line and one or more bypass lines connected to the supply line, comprising: a supply line cooling step of supplying liquefied gas from the storage tank through the supply line connected to the filling tank and cooling the supply line; a filling step of operating a compressor provided in the supply line and at least one of compressors provided in the one or more bypass lines, and filling the liquefied gas from the storage tank into the filling tank through the supply line and one or more bypass lines connected to the supply line, A method for filling liquefied gas, wherein the maximum filling rate of liquefied gas from the storage tank to the filling tank is 100 tons / hr or more.

[0015] [6] The method for filling a liquefied gas described in [5], further comprising a pressure equalization step of equalizing the pressure between the storage tank and the filling tank through a pressure equalization line connected to the storage tank and the filling tank before the supply line cooling step.

[0016] [7] A method for filling liquefied gas as described in [5] or [6], wherein, in the supply line cooling process, when the flow rate of the liquefied gas measured by a flow meter installed in the supply line falls below a predetermined value, the compressor installed in the supply line is started to increase the flow rate.

[0017] [8] A method for filling a liquefied gas according to any one of [5] to [7], wherein in the filling step, after confirming that the liquefied gas in the supply line is at liquid density using a fluid density measuring means provided between the connection between the supply line and the one or more bypass lines at the outlet side of the compressor provided in the supply line and the filling tank, at least one of the compressors provided in each of the one or more bypass lines is started to fill the liquefied gas from the storage tank into the filling tank.

[0018] [9] A method for filling a liquefied gas according to any one of [5] to [8], wherein when the liquid volume in the filling tank measured by a liquid volume measuring means provided in the filling tank reaches 80% by volume or more, the compressors provided in the one or more bypass lines are sequentially stopped.

[0019]

[10] The method for filling a liquefied gas according to any one of [5] to [9], wherein all of the compressors are stopped when the liquid volume in the filling tank reaches 90% by volume or more. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a liquefied gas filling system and a liquefied gas filling method that can suppress the occurrence of the water hammer phenomenon even when filling a large tank with liquefied gas and can efficiently fill large quantities of liquefied gas. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic configuration diagram of a liquefied gas filling system according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic configuration diagram of a liquefied gas filling system according to a second embodiment of the present invention. [Figure 3A] 2 is a flowchart (1) for explaining a liquefied gas filling method according to the first embodiment using the liquefied gas filling system of FIG. 1. [Figure 3B]10 is a flowchart (2) for explaining the liquefied gas filling method according to the first embodiment using the liquefied gas filling system of FIG. [Figure 3C] 10 is a flowchart (3) for explaining the liquefied gas filling method according to the first embodiment using the liquefied gas filling system of FIG. [Figure 4A] 10 is a flowchart (1) for explaining a liquefied gas filling method according to a second embodiment using the liquefied gas filling system of FIG. 2. [Figure 4B] 10 is a flowchart (2) for explaining the liquefied gas filling method according to the second embodiment using the liquefied gas filling system of FIG. [Figure 4C] 10 is a flowchart (3) for explaining the liquefied gas filling method according to the second embodiment using the liquefied gas filling system of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0022] The liquefied gas filling system and liquefied gas filling method of the present invention will be described in detail below based on embodiments thereof with reference to the drawings. Note that the drawings are used for explaining the present invention and may differ in actual dimensions.

[0023] In this specification, the expression "a to b" in the description of a range of values ​​means that the range is from a to b, unless otherwise specified.

[0024] <Liquefied gas filling system> [First embodiment] FIG. 1 is a schematic configuration diagram of a liquefied gas filling system 1 according to a first embodiment of the present invention.

[0025] As shown in Fig. 1, a liquefied gas filling system 1 according to the first embodiment includes a storage tank 2 that stores liquefied gas, a filling tank 3 that fills with liquefied gas, a supply line 4 connected to the storage tank 2 and the filling tank 3 and for supplying liquefied gas from the storage tank 2 to the filling tank 3, one or more bypass lines 5 connected to the supply line 4, and a compressor 6 provided on each of the supply line 4 and the one or more bypass lines 5. In the liquefied gas filling system 1, one end of the one or more bypass lines 5 is connected to the inlet side of the compressor 6 provided on the supply line 4, and the other end is connected to the outlet side of the compressor 6 provided on the supply line 4. In the liquefied gas filling system according to the first embodiment, the maximum filling rate of liquefied gas from the storage tank 2 to the filling tank 3 is 100 tons / hr or more. According to the above-described liquefied gas filling system, one or more bypass lines 5 are provided in addition to the supply line 4, and the supply line 4 and each bypass line 5 are provided with a compressor 6, so that the filling flow rate of the liquefied gas can be controlled. Therefore, it is possible to control the change in the flow rate of the liquefied gas in stages, which makes it possible to suppress the occurrence of the water hammer phenomenon and to fill a large amount of liquefied gas efficiently.

[0026] (storage tank) The storage tank 2 is a tank that contains the liquefied gas to be filled into the filling tank 3. The storage tank 2 is not limited to any particular type, but specific examples include cargo tanks. The size of the storage tank 2 is preferably 100 tons or more, more preferably 200 tons or more, and even more preferably 1,000 tons or more. The size of the storage tank 2 is preferably 100,000 tons or less, more preferably 50,000 tons or less, and even more preferably 20,000 tons or less.

[0027] (Filling tank) The filling tank 3 is a tank to be filled with liquefied gas. The filling tank 3 is connected to a supply line 4, which will be described later, and is filled with liquefied gas from a storage tank 2, which is also connected to the supply line 4, through the supply line 4 and one or more bypass lines 5, which will be described later. The filled tank 3 is not limited to, but may be, for example, a tank installed on a transport ship. The size of the filled tank 3 is preferably 100 tons or more, more preferably 200 tons or more, and even more preferably 1000 tons or more. The size of the filled tank 3 is preferably 100,000 tons or less, more preferably 50,000 tons or less, and even more preferably 20,000 tons or less.

[0028] The filling tank 3 may be provided with a liquid volume measuring means (not shown) for measuring the volume of liquefied gas filled. By providing the liquid volume measuring means in the filling tank 3, the volume of liquefied gas filled in the filling tank 3 can be measured, and the filling flow rate of the liquefied gas can be controlled in stages, particularly in the latter stage of filling the liquefied gas. More specifically, since the filling flow rate of the liquefied gas can be reduced in stages in the latter stage of filling the liquefied gas, the occurrence of the water hammer phenomenon can be further suppressed and large amounts of liquefied gas can be filled more efficiently. The liquid volume measuring means is not limited to, but may be, for example, a flow meter, a liquid level detector, or the like.

[0029] (supply line) The supply line 4 is a line for supplying liquefied gas from the storage tank 2 to the filling tank 3. The supply line 4 is connected to the storage tank 2 and the filling tank 3. In addition, one or more bypass lines 5 are provided on the supply line 4. By providing one or more bypass lines 5 in addition to the supply line 4, the liquefied gas can be supplied through multiple lines, and the filling flow rate of the liquefied gas can be controlled. The supply line 4 is not limited to a specific diameter, but may have a diameter of 80A or more, for example. The liquefied gas filling system of this embodiment has multiple lines, which allows the capacity of each compressor 6 to be reduced. Therefore, the diameter of the supply line 4 in the liquefied gas filling system 1 of this embodiment can be made smaller than when only one compressor is used, thereby preventing a large amount of liquefied gas from flowing all at once when the automatic valve 8 is opened.

[0030] The supply line 4 is provided with a compressor 6. The compressor 6 sends out liquefied gas from upstream to downstream. As described above, the supply line 4 is provided with one or more bypass lines 5, and the compressor 6 is provided in the supply line 4 between the connection point between the supply line 4 and the bypass line 5. As will be described later, a compressor 6 is also provided in the bypass line 5, and the flow rate of the liquefied gas to be supplied can be adjusted by adjusting the number of compressors 6 operating in the supply line 4 and the bypass line 5.

[0031] The compressor 6 is not limited to, but may be, for example, a centrifugal pump, a canned pump, or the like.

[0032] The compressor 6 preferably has a supply capacity of 50 tons / hr or more, more preferably 100 tons / hr or more, and even more preferably 200 tons / hr or more. The supply capacity of the compressor 6 is preferably 800 tons / hr or less. A plurality of compressors 6 may be installed on the supply line 4, and when a plurality of compressors 6 are installed, the supply capacities of the compressors 6 may be different from each other.

[0033] The supply line 4 may also be provided with an automatic valve 8. The supply of liquefied gas can be controlled by opening and closing the automatic valve 8. The automatic valve 8 is preferably provided between the connection between the supply line 4 and the bypass line 5. When the automatic valve 8 is provided in the supply line 4, the automatic valve 8 is closed at the start of filling. The opening and closing of the automatic valve 8 can be controlled by a control device (not shown).

[0034] The supply line 4 is at room temperature when the supply of liquefied gas begins. Therefore, after the start of supply, liquefied gas is flowed through the supply line 4 to cool the supply line 4. There are no limitations on the method for supplying liquefied gas to the supply line 4. For example, a small amount of liquefied gas can be supplied to the supply line 4 by opening an automatic valve 8 (V1 in FIG. 1) provided on the supply line 4 without operating the compressor 6.

[0035] A flow meter 7 may be provided in the supply line 4. The flow meter 7 measures the flow rate of the liquefied gas in the supply line 4. The flow meter 7 may be provided between the filling tank 3 and a connection between the supply line 4 and the bypass line 5 on the outlet side of the compressor 6 provided in the supply line 4. The location where the flow meter 7 is provided is not limited thereto, and the flow meter 7 may be provided in another location in the supply line 4.

[0036] It is preferable that a fluid density measuring means is provided in the supply line 4. The fluid density measuring means measures the density of the liquefied gas supplied to the supply line 4. The fluid density measuring means may be provided in the supply line 4, between the junction of the supply line 4 and the bypass line 5 on the outlet side of the compressor 6 and the filling tank 3. However, the location is not limited to this and the fluid density measuring means may be provided in another location on the supply line 4. The fluid density measuring means may be, for example, a liquid density meter, etc. Alternatively, the fluid density measuring means may be the above-mentioned flow meter 7 that can measure density.

[0037] (Bypass line) One or more bypass lines 5 (hereinafter sometimes simply referred to as "bypass lines 5") are connected to the supply line 4. More specifically, one or more bypass lines 5 have one end connected to the inlet side of a compressor 6 (P1 in FIG. 1) provided on the supply line 4, and the other end connected to the outlet side of the compressor 6 (P1). The number of bypass lines 5 is not limited, but from the viewpoint of enabling precise adjustment of the flow rate of the liquefied gas, it is preferable that the number be two or more, and more preferably three or more. Furthermore, from the viewpoint of balancing between reducing the complexity of control and adjusting the flow rate, it is preferable that the number of bypass lines 5 be five or less, and more preferably four or less.

[0038] Each of the one or more bypass lines 5 has a compressor 6 (P2 to P4 in FIG. 1). The compressors 6 in the bypass lines 5 can be configured in the same manner as described above for the compressors 6 in the supply line 4. Furthermore, the compressors 6 in the bypass lines 5 may have different supply capacities.

[0039] One or more bypass lines 5 may each have an automatic valve 8 (V2 to V4 in FIG. 1). The automatic valve 8 can control whether liquefied gas is supplied through the bypass line 5. The automatic valve 8 is closed at the start of filling. The opening and closing of the automatic valve 8 is controlled by a control device (not shown).

[0040] In FIG. 1, one or two bypass lines 5 are formed by branching one line connected to the supply line 4 into multiple lines, which are combined into one line on the outlet side of the compressor 6 and the automatic valve 8 and connected to the supply line 4, but each of the bypass lines 5 may be connected to the supply line 4.

[0041] In the liquefied gas filling system 1 according to the first embodiment of the present invention, in addition to the supply line 4, one or more bypass lines 5 are provided, and a compressor 6 is provided in each of the supply line 4 and the one or more bypass lines 5, so that the filling amount of liquefied gas can be controlled by controlling the number of operating compressors 6. This prevents abrupt changes in the flow rate of liquefied gas, suppresses the occurrence of the water hammer phenomenon, and allows for efficient filling of large amounts of liquefied gas. Furthermore, even if the water hammer phenomenon does occur, impact can be suppressed. In addition, because there are multiple lines and compressors for supplying liquefied gas, even if one or more compressors fail, liquefied gas can still be filled through the line with the remaining compressors.

[0042] (liquefied gas) The liquefied gas is preferably liquefied carbon dioxide.

[0043] In the liquefied gas filling system of this embodiment, the maximum filling rate of liquefied gas is 100 tons / hr or more. The maximum filling rate of liquefied gas is the maximum amount of liquefied gas that can be filled from the storage tank 2 to the filling tank 3, and is preferably 200 tons / hr or more and 800 tons / hr or less. The maximum filling rate of liquefied gas can be measured by providing a measuring means such as a flow meter on the supply line 4 or by providing a measuring means such as a flow meter on the filling tank 3.

[0044] [Second embodiment] Fig. 2 is a schematic diagram of a liquefied gas filling system 11 according to a second embodiment of the present invention. In Fig. 2, components common to Fig. 1 are given the same reference numerals. Fig. 2 is similar to Fig. 1 except that it is provided with a pressure equalization line 9. For the liquefied gas filling system 11 according to the second embodiment, the description of the liquefied gas filling system 1 according to the first embodiment can be used for the description other than the pressure equalization line 9.

[0045] As shown in FIG. 2, a liquefied gas filling system 11 according to a second embodiment of the present invention has a pressure equalization line 9 connected to a storage tank 2 and a filling tank 3. The pressure equalization line 9 is a line for equalizing the pressure between the storage tank 2 and the filling tank 3. Vaporized gas is supplied from the filling tank 3 to the storage tank 2 via the pressure equalization line 9. By supplying vaporized gas from the filling tank 3 to the storage tank 2 via the pressure equalization line 9, the pressures of the storage tank 2 and the filling tank 3 become the same. By equalizing the pressures of the storage tank 2 and the filling tank 3 in this way, the pressure of the storage tank 2 can be increased, and therefore, for example, if the liquefied gas is liquefied carbon dioxide, it is possible to prevent dry ice from forming due to a drop in pressure.

[0046] The liquefied gas filling system of this embodiment may be provided in parallel to fill a plurality of filling tanks.

[0047] <How to fill liquefied gas> The liquefied gas filling method of this embodiment includes: A method for filling a liquefied gas, in which the liquefied gas is filled from a storage tank (2) into a filling tank (3) through a supply line (4) and one or more bypass lines (5) connected to the supply line (4), comprising the steps of: a supply line cooling step of supplying liquefied gas from the storage tank 2 through the supply line 4 connected to the filling tank 3 and cooling the supply line 4; a filling step of operating a compressor 6 provided in the supply line 4 and at least one of the compressors 6 provided in the one or more bypass lines 5, and filling the liquefied gas from the storage tank 2 into the filling tank 3 through the supply line 4 and the one or more bypass lines 5 connected to the supply line 4, The maximum amount of liquefied gas that can be filled from the storage tank 2 to the filling tank 3 is 100 tons / hr or more. With the above-described method for filling liquefied gas, even when filling a large tank with liquefied gas, the occurrence of the water hammer phenomenon can be suppressed, and a large amount of liquefied gas can be filled efficiently.

[0048] The liquefied gas filling method of this embodiment will be described below with reference to the flowcharts of Figures 3A to 3C and 4A to 4C. Figures 3A to 3C are flowcharts for explaining the liquefied gas filling method according to a first embodiment using the liquefied gas filling system of Figure 1. Figures 4A to 4C are flowcharts for explaining the liquefied gas filling method according to a second embodiment using the liquefied gas filling system of Figure 2.

[0049] [First embodiment] A liquefied gas filling method according to a first embodiment of the present invention will be described in detail with reference to FIGS. 3A to 3C.

[0050] (Supply line cooling process) In the liquefied gas filling method of this embodiment, first, liquefied gas is supplied from the storage tank 2 through the supply line 4 connected to the filling tank 3, and the supply line 4 is cooled (supply line cooling step).

[0051] Specifically, the automatic valve 8 (V1 and V6 in FIGS. 1 and 2) provided on the supply line 4 is opened (S1), and liquefied gas is allowed to flow from the storage tank 2 into the supply line 4 to begin cooling the supply line 4. At this time, the flow rate of the liquefied gas in the supply line 4 is measured using the flow meter 7 provided on the supply line 4 (S2). In S2, it is determined whether the flow rate of the liquefied gas measured by the flow meter 7 has fallen below a predetermined value. If the result in S2 is YES, the compressor 6 provided on the supply line 4 is started (S3), and the flow rate of the liquefied gas being supplied is increased to cool the supply line 4. The predetermined value of the flow rate of the liquefied gas used to determine whether to start the compressor 6 is not limited, and may be, for example, a value when the flow rate of the liquefied gas has dropped by 50% compared to the flow rate at the start of supply.

[0052] If all of the compressors 6 provided in the supply line 4 and the bypass line 5 are started and liquefied gas is supplied while gas remains in the supply line 4, there is a risk of water hammer occurring. In this way, by cooling the supply line 4 by passing liquefied gas through it before filling the tank with the liquefied gas, it is possible to prevent the liquefied gas from being present in gaseous form in the supply line 4, thereby suppressing the occurrence of the water hammer.

[0053] (filling process) Following the supply line cooling process, the compressor 6 provided in the supply line 4 and at least one of the compressors 6 provided in one or more bypass lines 5 are operated, and liquefied gas is filled from the storage tank 2 into the filling tank 3 through the supply line 4 and one or more bypass lines 5 connected to the supply line 4 (filling process).

[0054] Specifically, the density of the liquefied gas is measured by a liquid density measuring means provided in the supply line 4 (S4). Once it is confirmed in S4 that the density of the liquefied gas is liquid density, the automatic valves 8 (V2 to V4) provided in one or more bypass lines 5 are opened (S5) while continuing to operate the compressor 6 that was started in the supply line cooling step described above, and the compressors 6 (V2 to V4) are started sequentially (S6). Note that the density of the liquefied gas being liquid density means that the density indication measured by the fluid density measuring means is equal to or greater than the liquid density. For example, the liquid density of carbon dioxide is 1.030 kg / L (-20°C, 1.967 MPa). As described above, by starting the compressor 6 in sequence after it has been confirmed that the supply line 4 has been cooled and the liquefied gas has reached liquid density, it is possible to prevent the occurrence of the water hammer phenomenon.

[0055] In the filling method of this embodiment, the maximum filling rate of liquefied gas from the storage tank 2 to the filling tank 3 is 100 tons / hr or more. The maximum filling rate of liquefied gas is the maximum filling rate of liquefied gas from the storage tank 2 to the filling tank 3, and is preferably 200 tons / hr or more and 800 tons / hr or less. The maximum filling rate of liquefied gas can be measured by providing a measuring means such as a flow meter in the supply line 4 or by providing a measuring means such as a flow meter in the filling tank 3.

[0056] In the method for filling liquefied gas of this embodiment, it is preferable that the filling of the filling tank 3 with liquefied gas is completed by successively stopping the compressors 6. In the liquefied gas filling method of this embodiment, when the liquid volume in the filling tank 3 measured by a liquid volume measuring means provided in the filling tank 3 reaches 80% by volume or more, the compressors 6 provided in one or more bypass lines 5 are stopped sequentially. In addition, in the liquefied gas filling method of this embodiment, when the liquid volume in the filling tank 3 measured by the liquid volume measuring means provided in the filling tank 3 reaches 90% by volume or more, all compressors 6 are stopped.

[0057] Specifically, the amount of liquefied gas filled in the filling tank 3 is measured by a flow rate measuring means provided in the filling tank 3 (S7). When the amount of liquefied gas measured in S7 reaches 80% by volume of the filling tank 3, the compressors 6 provided in one or more bypass lines 5 are stopped in sequence so that there are only two operating compressors 6 (S8). At this time, the automatic valve 8 provided in the line where the compressor 6 has been stopped is closed (S8).

[0058] Next, the flow rate of the liquefied gas filled in the filling tank 3 is measured by a flow rate measuring means provided in the filling tank 3 (S9). In S9, when the liquid volume in the filling tank 3 reaches 85% by volume, the compressors 6 are stopped so that only one compressor 6 is in operation (S10). At this time, the automatic valve 8 provided on the line where the compressor 6 has been stopped is closed (S10).

[0059] Thereafter, the flow rate of the liquefied gas filled in the filling tank 3 is measured by a flow rate measuring means provided in the filling tank 3 (S11). When the liquid volume in the filling tank 3 reaches 90% by volume in S11, all of the operating compressors 6 are stopped in sequence (S12), and the automatic valves 8 provided on the lines where the compressors 6 have been stopped are closed to complete the filling. In this way, by gradually stopping the operating compressor 6 based on the amount of liquid filled in the filling tank 3, the flow rate of the liquefied gas being filled can be gradually reduced, thereby suppressing the occurrence of the water hammer phenomenon. This also stabilizes the temperature and pressure inside the filling tank 3, preventing pressure fluctuations after filling.

[0060] [Second embodiment] A liquefied gas filling method according to a second embodiment of the present invention will be described in detail with reference to Figures 4A to 4C. Only the differences between the liquefied gas filling method according to the second embodiment and the liquefied gas filling method according to the first embodiment will be described.

[0061] The liquefied gas filling method according to the second embodiment includes a pressure equalization step before the supply line cooling step. The liquefied gas filling method according to the second embodiment differs from the liquefied gas filling method according to the first embodiment in that it includes a pressure equalization step. In the pressure equalization step, the storage tank 2 and the filling tank 3 are equalized in pressure through a pressure equalization line 9 connected to the storage tank 2 and the filling tank 3.

[0062] Specifically, the automatic valves 8 (V6 and V7) in the pressure equalization line 9 are opened (S41). This equalizes the pressure in the storage tank 2 and the filling tank 3 (S42). After equalizing the pressure in the storage tank 2 and the filling tank 3 in this way, the process proceeds to S1. By providing a pressure equalization process before the supply line cooling process, the storage tank 2 and the filling tank 3 can be made to have the same pressure, and the storage tank 2 can be pressurized.For example, if the liquefied gas is liquefied carbon dioxide, it is possible to prevent the gas from turning into dry ice due to a drop in pressure.

[0063] In the liquefied gas filling method of the second embodiment, the supply line cooling process and filling process, etc. are similar to those of the liquefied gas filling method of the first embodiment, and the explanation of the liquefied gas filling method of the first embodiment can be applied.

[0064] In the liquefied gas filling method of the present invention, the start and stop of the compressor 6 and the opening and closing of the automatic valve 8 can be controlled by a control device not shown.

[0065] Although the present invention has been described with reference to the drawings, it should be noted that those skilled in the art would easily be able to make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present invention. For example, the functions of each component, each step, etc. can be rearranged so as not to cause logical inconsistencies, and multiple components, steps, etc. can be combined or divided into one. [Industrial Applicability]

[0066] According to the present invention, a liquefied gas filling system and a liquefied gas filling method can be provided that can suppress the occurrence of the water hammer phenomenon even when filling a large tank with liquefied gas, and can efficiently fill large quantities of liquefied gas. [Explanation of symbols]

[0067] 1,11: Liquefied gas filling system 2: Storage tank 3: Filling tank 4: Supply line 5: Bypass line 6: Compressor 7:Flow meter 8: Automatic valve 9: Pressure equalizing line

Claims

1. a storage tank for storing liquefied gas; a filling tank for filling the liquefied gas; a supply line connected to the storage tank and the filling tank for supplying liquefied gas from the storage tank to the filling tank; one or more bypass lines connected to the supply line; a compressor provided in each of the supply line and the one or more bypass lines, one end of the one or more bypass lines is connected to an inlet side of the compressor provided in the supply line, and the other end is connected to an outlet side of the compressor provided in the supply line, A liquefied gas filling system in which the maximum filling rate of liquefied gas from the storage tank to the filling tank is 100 tons / hr or more.

2. 2. The liquefied gas filling system according to claim 1, further comprising a fluid density measuring means in the supply line between the connection between the supply line and the bypass line on the outlet side of the compressor provided in the supply line and the filling tank.

3. 3. The liquefied gas filling system according to claim 1, wherein the filling tank has a liquid amount measuring means for measuring the amount of the liquefied gas filled in the tank.

4. 3. The liquefied gas filling system according to claim 1, further comprising a pressure equalization line connected to the storage tank and the filling tank for equalizing the pressure between the storage tank and the filling tank.

5. A method for filling a liquefied gas into a filling tank from a storage tank through a supply line and one or more bypass lines connected to the supply line, comprising: a supply line cooling step of supplying liquefied gas from the storage tank through the supply line connected to the filling tank and cooling the supply line; a filling step of operating a compressor provided in the supply line and at least one of compressors provided in the one or more bypass lines, and filling the liquefied gas from the storage tank into the filling tank through the supply line and one or more bypass lines connected to the supply line, A method for filling liquefied gas, wherein the maximum filling rate of the liquefied gas from the storage tank to the filling tank is 100 tons / hr or more.

6. 6. The method for filling liquefied gas according to claim 5, further comprising a pressure equalization step of equalizing the pressure between the storage tank and the filling tank through a pressure equalization line connected to the storage tank and the filling tank before the supply line cooling step.

7. 7. A method for filling liquefied gas as described in claim 5 or 6, wherein, in the supply line cooling step, when the flow rate of the liquefied gas measured by a flow meter provided in the supply line becomes equal to or lower than a predetermined value, the compressor provided in the supply line is started to increase the flow rate.

8. 7. The method for filling a liquefied gas according to claim 5 or 6, wherein in the filling step, after confirming that the liquefied gas in the supply line is at liquid density using a fluid density measuring means provided between the filling tank and a connection between the supply line and the one or more bypass lines at the outlet side of the compressor provided in the supply line, at least one of the compressors provided in each of the one or more bypass lines is started to fill the liquefied gas from the storage tank into the filling tank.

9. 9. The method for filling liquefied gas according to claim 8, wherein the compressors provided in the one or more bypass lines are sequentially stopped when the liquid volume in the filling tank measured by a liquid volume measuring means provided in the filling tank reaches 80% by volume or more.

10. 9. The method for filling liquefied gas according to claim 8, wherein all of the compressors are stopped when the amount of liquid in the filling tank reaches 90% by volume or more.

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