Liquefied gas filling system and method for filling liquefied gas
The liquefied gas filling system with bypass lines and compressors addresses water hammer issues in large-scale tank filling by controlling flow rates, achieving efficient and stable liquefied gas transfer.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NIPPON SANSO CORP
- Filing Date
- 2024-03-28
- Publication Date
- 2026-05-12
AI Technical Summary
Large-scale transportation of liquefied gases into large tanks is prone to water hammer phenomena due to rapid flow rate changes, which existing methods struggle to manage efficiently, often requiring costly valves and instruments.
A liquefied gas filling system with bypass lines and compressors in both the supply line and bypass lines, allowing controlled flow rate adjustments to suppress water hammer and enable efficient filling of large quantities.
The system effectively suppresses water hammer occurrences and enables efficient filling of large tanks with liquefied gas by controlling flow rates through multiple lines and compressors, ensuring stable filling processes.
Smart Images
Figure 0007856879000001 
Figure 0007856879000002 
Figure 0007856879000003
Abstract
Description
Technical Field
[0001] The present invention relates to a liquefied gas filling system and a method for filling liquefied gas.
Background Art
[0002] Conventionally, liquefied gases such as liquefied carbon dioxide and liquefied petroleum gas have been filled from tank to tank. As for the filling of liquefied gas from tank to tank, for example, the filling of liquefied gas from the tank of a tank truck to a tank to be filled is performed. At the time of such filling, usually, the compressor is operated at high speed from the start of filling to fill the liquefied gas into the tank, the operator checks the filling amount with a measuring instrument, and when the predetermined filling amount is reached, the operator manually stops the compressor to finish the filling of the liquefied gas into the tank.
[0003] For example, in Patent Document 1, a liquefied petroleum gas filling device is disclosed that includes a liquid transfer line connecting the liquid phase part of a tanker tank and the gas phase part of a bulk container via a pump, and a gas phase line connecting the gas phase parts of the tanker tank and the bulk container.
[0004] In addition, in the filling of liquefied gas into a tank, the flow rate of the liquefied gas is adjusted by controlling a valve. For example, in Patent Document 2, a liquefied gas filling system is disclosed that includes a liquefied gas filling path with one end connected to the liquid phase region of a liquefied gas storage tank and the other end connected to the liquid phase region of a fuel tank, a gas phase region pressure equalization path with one end connected to the 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 the liquid level detection data transmitted by the transmitting means, a filling start operation unit operated when starting to fill the liquefied gas in the liquefied gas storage tank into the fuel tank, a control means for controlling the filling amount of the liquefied gas filled into the fuel tank, and the like.
Prior Art Documents
[0005] [Patent Document 1] Japanese Patent Publication No. 2000-291889 [Patent Document 2] Japanese Patent Publication No. 2010-255809 [Overview of the project] [Problems that the invention aims to solve]
[0006] Recently, the need for large-scale transportation of liquefied gases such as liquefied carbon dioxide has increased. In such large-scale transportation of liquefied gases, the gases are filled into large tanks, such as cargo tanks on large transport ships.
[0007] When filling large tanks with liquefied gas as described above, unlike when filling relatively small amounts of liquefied gas from a tank truck's tank to a storage tank, the amount to be filled into the tank is large and the filling takes time, so it is necessary to automatically check the filling amount and operate accordingly. In addition, when filling large tanks with liquefied gas as described above, the flow rate of liquefied gas during filling is large and the flow rate changes are also large. Therefore, if the method used for filling relatively small amounts of liquefied gas is used, a water hammer phenomenon may occur, and the impact of this can be large. Patent document 2 above controls the filling flow rate by measuring the amount to be filled into the tank and controlling the opening and closing of a valve to reduce the impact of the water hammer phenomenon, but such technology requires many valves and measuring instruments, which can be costly, so there is a need for a way to suppress the water hammer phenomenon by other means.
[0008] Therefore, the object of the present invention is to solve the problems of the above-mentioned prior art 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] The inventors of the present invention conducted diligent studies to solve the above problems and found that by providing one or more bypass lines in the supply line and a compressor in both the supply line and the bypass lines, the filling amount can be adjusted, thereby suppressing the water hammer phenomenon and enabling efficient filling of large quantities of liquefied gas. This led to the completion of the present invention. The gist of the liquefied gas filling system and liquefied gas filling method of the present invention, which solves the above problems, is as follows.
[0010] [1] A storage tank for storing liquefied gas, A filling tank for filling with liquefied gas, A supply line connected to the storage tank and the filling tank, which supplies liquefied gas from the storage tank to the filling tank, One or more bypass lines connected to the supply line, The system comprises a compressor provided in each of the supply line and the one or more bypass lines, The one or more bypass lines are connected in the supply line to the inlet side of the compressor provided in the supply line, and to the outlet side of the compressor provided in the supply line, A liquefied gas filling system in which the maximum amount of liquefied gas to be filled from the storage tank to the filling tank is 100 tons / hr or more.
[0011] [2] The liquefied gas filling system according to [1], wherein the supply line has a fluid density measuring means between the connection between the supply line and the bypass line and the filling tank on the outlet side of the compressor provided in the supply line.
[0012] [3] The 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 for equalizing the pressure between the storage tank and the filling tank.
[0014] [5] A method for filling a filling tank from a storage tank with liquefied gas through a supply line and one or more bypass lines connected to the supply line, A supply line cooling step involves supplying liquefied gas from the storage tank through the supply line connected to the filling tank and cooling the supply line, A filling step includes operating a compressor provided in the supply line and at least one of the compressors provided in the one or more bypass lines, and filling the filling tank from the storage tank through the supply line and one or more bypass lines connected to the supply line, A method for filling a liquefied gas, wherein the maximum amount of liquefied gas to be filled from the storage tank to the filling tank is 100 tons / hr or more.
[0015] [6] The method for filling a liquefied gas according to [5], further comprising a pressure equalization step of equalizing the pressure of the storage tank and the filling tank through a pressure equalization line connected to the storage tank and the filling tank, prior to the supply line cooling step.
[0016] [7] The method for filling liquefied gas according to [5] or [6], wherein in the supply line cooling step, when the flow rate of 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 activated to increase the flow rate.
[0017] [8] In the filling step, after it is confirmed by the fluid density measuring means provided between the connection portion of the supply line and the one or more bypass lines on the outlet side of the compressor provided in the supply line and the filling tank that the liquefied gas in the supply line is at a liquid density, at least one of the compressors provided in each of the one or more bypass lines is started to fill the filling tank with liquefied gas from the storage tank, the method for filling liquefied gas according to any one of [5] to [7].
[0018] [9] When the liquid volume of the filling tank measured by the 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, the method for filling liquefied gas according to any one of [5] to [8].
[0019]
[10] When the liquid volume of the filling tank reaches 90% by volume or more, all the compressors are stopped, the method for filling liquefied gas according to any one of [5] to [9]. [Advantages of the Invention]
[0020] According to the present invention, even when filling a large tank with liquefied gas, it is possible to provide a liquefied gas filling system and a method for filling liquefied gas that can suppress the occurrence of water hammer phenomenon and efficiently fill a large amount of liquefied gas. [Brief Description of the Drawings]
[0021] [Figure 1] It is a schematic configuration diagram of a liquefied gas filling system according to a first embodiment of the present invention. [Figure 2] It is a schematic configuration diagram of a liquefied gas filling system according to a second embodiment of the present invention. [Figure 3A] It is a flowchart (1) for explaining a method for filling liquefied gas according to a first embodiment by the liquefied gas filling system of FIG. 1. [Figure 3B]This is a flowchart (2) illustrating the method of filling with liquefied gas according to the first embodiment using the liquefied gas filling system shown in Figure 1. [Figure 3C] This is a flowchart (3) illustrating the method of filling with liquefied gas according to the first embodiment using the liquefied gas filling system shown in Figure 1. [Figure 4A] This is a flowchart (1) illustrating the method of filling with liquefied gas according to the second embodiment using the liquefied gas filling system shown in Figure 2. [Figure 4B] This is a flowchart (2) illustrating the method of filling with liquefied gas according to the second embodiment using the liquefied gas filling system shown in Figure 2. [Figure 4C] This is a flowchart (3) illustrating the method of filling with liquefied gas according to the second embodiment using the liquefied gas filling system shown in Figure 2. [Modes for carrying out the invention]
[0022] The liquefied gas filling system and the 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 to illustrate the present invention and may differ from actual dimensions.
[0023] In this specification, the notation "a~b" in descriptions of numerical ranges means a or greater and b or less, unless otherwise specified.
[0024] <Liquefied Gas Filling System> [First Embodiment] Figure 1 is a schematic diagram of a liquefied gas filling system 1 according to the first embodiment of the present invention.
[0025] As shown in Figure 1, the liquefied gas filling system 1 according to the first embodiment includes a storage tank 2 for storing liquefied gas, a filling tank 3 for filling with 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 more bypass lines 5 connected to the supply line 4, and compressors 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 or more bypass lines 5 have one end connected to the inlet side of the compressor 6 provided on the supply line 4, and the other end connected to the outlet side of the compressor 6 provided on the supply line 4. The maximum amount of liquefied gas to be filled from the storage tank 2 to the filling tank 3 in the liquefied gas filling system according to the first embodiment is 100 tons / hr or more. According to the above-described liquefied gas filling system, in addition to the supply line 4, one or more bypass lines 5 are provided, and compressors 6 are installed in the supply line 4 and each bypass line 5, allowing the filling flow rate of the liquefied gas to be controlled. Therefore, since it is possible to control the change in the flow rate of the liquefied gas in stages, the occurrence of the water hammer phenomenon can be suppressed, and a large amount of liquefied gas can be filled efficiently.
[0026] (Storage tank) Storage tank 2 is a tank that contains liquefied gas to be filled into filling tank 3. Storage tank 2 is not limited to this, but specifically, examples include cargo tanks. The size of storage tank 2 is preferably 100 tons or more, more preferably 200 tons or more, and even more preferably 1,000 tons or more. Furthermore, the size of 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 into which liquefied gas is filled. The filling tank 3 is connected to the supply line 4 described later, and liquefied gas is filled from the storage tank 2, which is also connected to the supply line 4, through the supply line 4 and one or more bypass lines 5 described later. The filling tank 3 is not limited to any particular type, but examples include tanks installed on transport ships. The size of the filling tank 3 is preferably 100 tons or more, more preferably 200 tons or more, and even more preferably 1,000 tons or more. Furthermore, the size of the filling 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 equipped with a liquid volume measuring means (not shown) for measuring the amount of liquefied gas filled into it. The presence of this liquid volume measuring means in the filling tank 3 allows for the measurement of the amount of liquefied gas filled into the tank 3, and particularly in the later stages of liquefied gas filling, allows for the gradual control of the liquefied gas filling flow rate. More specifically, by gradually reducing the liquefied gas filling flow rate in the later stages of liquefied gas filling, the occurrence of water hammer can be further suppressed, and a larger volume of liquefied gas can be filled more efficiently. Means of measuring liquid volume are not limited to these, but examples include flow meters and liquid level detection devices.
[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 both the storage tank 2 and the filling tank 3. In addition, the supply line 4 is provided with one or more bypass lines 5. 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 thus the filling flow rate of the liquefied gas can be controlled. The supply line 4 is not limited, but can have a diameter of 80A or more, for example. The liquefied gas filling system of this embodiment can reduce the capacity of each compressor 6 by having multiple lines. 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] A compressor 6 is provided in the supply line 4. The compressor 6 sends liquefied gas from upstream to downstream. As described above, one or more bypass lines 5 are provided in the supply line 4, and the compressor 6 is provided in the supply line 4 between the connection point between the supply line 4 and the bypass lines 5. Furthermore, as will be described later, a compressor 6 is also provided in the bypass line 5, and the flow rate of the supplied liquefied gas 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 can include, for example, a centrifugal pump, a canned pump, etc.
[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. Furthermore, the supply capacity of the compressor 6 is preferably 800 tons / hr or less. Multiple compressors 6 may be installed in the supply line 4, and if multiple compressors 6 are installed, their supply capacities may be varied.
[0033] Furthermore, an automatic valve 8 may be provided in the supply line 4. The supply of liquefied gas can be controlled by opening and closing the automatic valve 8. Preferably, the automatic valve 8 is provided between the connection point between the supply line 4 and the bypass line 5. If the automatic valve 8 is provided in the supply line 4, the automatic valve 8 is closed when filling starts. 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 supply begins, the liquefied gas is flowed through the supply line 4 to cool it down. The method of supplying liquefied gas to the supply line 4 is not limited, but for example, a small amount of liquefied gas can be supplied to the supply line 4 by opening the automatic valve 8 (V1 in Figure 1) provided in 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 liquefied gas in the supply line 4. The flow meter 7 may be installed between the connection point between the supply line 4 and the bypass line 5 on the outlet side of the compressor 6 provided in the supply line 4, and the filling tank 3. However, the location of the flow meter 7 is not limited to this, and it may be installed at other locations in the supply line 4.
[0036] Preferably, the supply line 4 is provided with a fluid density measuring means. 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 connection point between the supply line 4 and the bypass line 5 on the outlet side of the compressor 6 and the filling tank 3. However, it is not limited to this, and may be provided at other locations in the supply line 4. Examples of fluid density measuring means include a liquid density meter. Alternatively, the fluid density measuring means may be the aforementioned flow meter 7 capable of measuring 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 the compressor 6 (P1 in Figure 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 being able to finely adjust the flow rate of liquefied gas, it is preferable to have two or more, and more preferable to have three or more. Furthermore, from the viewpoint of balancing the suppression of control complexity and flow rate adjustment, it is preferable to have five or fewer bypass lines 5, and more preferable to have four or fewer.
[0038] Each of the one or more bypass lines 5 has a compressor 6 (P2 to P4 in Figure 1). The compressors 6 in the bypass lines 5 can be described in the same way as those described above for the compressors 6 in the supply line 4. In addition, the compressors 6 in the bypass lines 5 may each have different supply capacities.
[0039] One or more bypass lines 5 may each have an automatic valve 8 (V2 to V4 in Figure 1). The automatic valves 8 can supply or control liquefied gas through the bypass lines 5. The automatic valves 8 are closed at the start of filling. The opening and closing of the automatic valves 8 are controlled by a control device (not shown).
[0040] In Figure 1, one or two bypass lines 5 are formed when one line connected to the supply line 4 branches into multiple lines, which then merge into a single line at the outlet side of the compressor 6 and automatic valve 8 and are connected to the supply line 4. Alternatively, 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, one or more bypass lines 5 are provided in addition to the supply line 4, and a compressor 6 is provided in each of the supply line 4 and the one or more bypass lines 5. By controlling the number of operating compressors 6, the amount of liquefied gas filled can be controlled. This prevents sudden changes in the flow rate of the liquefied gas, thereby suppressing the occurrence of water hammer and enabling efficient filling of large quantities of liquefied gas. Furthermore, even if water hammer occurs, the impact can be suppressed. In addition to these, because there are multiple lines supplying liquefied gas and multiple compressors, even if one or more compressors fail, liquefied gas can still be filled through lines equipped with working compressors.
[0042] (Liquefied gas) Liquefied carbon dioxide is preferred as the liquefied gas.
[0043] In the liquefied gas filling system of this embodiment, the maximum liquefied gas filling rate is 100 tons / hr or more. The maximum liquefied gas filling rate is the maximum amount of liquefied gas to be filled from the storage tank 2 to the filling tank 3, and is preferably 200 tons / hr or more, and preferably 800 tons / hr or less. The maximum liquefied gas filling rate can be measured by providing measuring means such as a flow meter in the supply line 4 or by providing measuring means such as a flow meter in the filling tank 3.
[0044] [Second Embodiment] Figure 2 is a schematic diagram of a liquefied gas filling system 11 according to a second embodiment of the present invention. In Figure 2, components common to Figure 1 are denoted by the same reference numerals. Figure 2 is the same as Figure 1 except that it includes a pressure equalization line 9. In the liquefied gas filling system 11 according to the second embodiment, the description of components other than the pressure equalization line 9 can be explained by referring to the description of the liquefied gas filling system 1 according to the first embodiment.
[0045] As shown in Figure 2, the liquefied gas filling system 11 according to the 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 storage tank 2 and the filling tank 3 become equal in pressure. Since the storage tank 2 can be pressurized by making the storage tank 2 and the filling tank 3 equal in pressure in this way, for example, if the liquefied gas is liquefied carbon dioxide, it is possible to prevent it from turning into dry ice due to a pressure drop.
[0046] Furthermore, the liquefied gas filling system of this embodiment may be arranged in parallel, and multiple filling tanks may be filled.
[0047] <Method for filling with liquefied gas> The method for filling with liquefied gas in this embodiment is: A method for filling a filling tank 3 with liquefied gas, comprising filling a filling tank 3 from a storage tank 2 through a supply line 4 and one or more bypass lines 5 connected to the supply line 4, A supply line cooling step involves 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 is included in which 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 are operated to fill the filling tank 3 with liquefied gas from the storage tank 2 through the supply line 4 and 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 method of filling liquefied gas, even when filling large tanks with liquefied gas, the occurrence of water hammer can be suppressed, and a large amount of liquefied gas can be efficiently filled.
[0048] The method for filling with liquefied gas according to this embodiment will be explained below with reference to the flowcharts in Figures 3A to 3C and Figures 4A to 4C. Figures 3A to 3C are flowcharts illustrating the method for filling with liquefied gas according to the first embodiment using the liquefied gas filling system of Figure 1. Figures 4A to 4C are flowcharts illustrating the method for filling with liquefied gas according to the second embodiment using the liquefied gas filling system of Figure 2.
[0049] [First Embodiment] A method for filling with liquefied gas according to the first embodiment of the present invention will be described in detail with reference to Figures 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 valves 8 (V1 and V6 in Figures 1 and 2) installed in the supply line 4 are opened (S1), and liquefied gas is supplied from the storage tank 2 to 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 by a flow meter 7 installed in 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 answer in S2 is YES, the compressor 6 installed in the supply line 4 is started (S3), and the flow rate of the supplied liquefied gas is increased to cool the supply line 4. The predetermined value of the liquefied gas flow rate used to determine whether to start the compressor 6 is not limited, but for example, the value when the flow rate of the liquefied gas has decreased by 50% compared to the flow rate at the start of supply may be used as the predetermined value.
[0052] If gas is accumulating in supply line 4 and all compressors 6 installed in supply line 4 and bypass line 5 are started to supply liquefied gas, there is a risk of causing a water hammer phenomenon. Thus, by cooling supply line 4 by passing liquefied gas through it before filling the tank with liquefied gas, it is possible to prevent the liquefied gas from existing in gaseous form in supply line 4, thereby suppressing the occurrence of the water hammer phenomenon.
[0053] (filling process) Following the supply line cooling process, the compressor 6 installed in the supply line 4 and at least one of the compressors 6 installed in one or more bypass lines 5 are activated to fill the filling tank 3 from the storage tank 2 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 installed in the supply line 4 (S4). In S4, once it is confirmed that the density of the liquefied gas is the liquid density, the compressor 6, which was started in the supply line cooling process described above, continues to operate, and one or more automatic valves 8 (V2~V4) installed in the bypass line 5 are opened (S5), and the compressors 6 (V2~V4) are started sequentially (S6). Note that the density of the liquefied gas being the liquid density means that the density indicated 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℃, 1.967 MPa). As described above, by sequentially starting the compressor 6 after the supply line 4 has been cooled and it has been confirmed that the liquefied gas has a liquid density, the occurrence of the water hammer phenomenon can be suppressed.
[0055] In the filling method of this embodiment, the maximum amount of liquefied gas to be filled from the storage tank 2 to the filling tank 3 is 100 tons / hr or more. The maximum amount of liquefied gas to be filled is the maximum amount of liquefied gas to be filled from the storage tank 2 to the filling tank 3, and is preferably 200 tons / hr or more, and preferably 800 tons / hr or less. The maximum amount of liquefied gas to be filled can be measured by providing measuring means such as a flow meter in the supply line 4 or by providing measuring means such as a flow meter in the filling tank 3.
[0056] In the liquefied gas filling method of this embodiment, it is preferable to sequentially stop the compressor 6 to complete the filling of the filling tank 3 with liquefied gas. In the liquefied gas filling method of this embodiment, when the liquid volume in the filling tank 3, as measured by the 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 sequentially stopped. Furthermore, in the liquefied gas filling method of this embodiment, when the liquid volume in the filling tank 3, as 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% of the volume of the filling tank 3, the compressors 6 provided in one or more bypass lines 5 are sequentially stopped so that there are two compressors 6 in operation (S8). At this time, the automatic valves 8 provided in the lines where the compressors 6 were stopped are also 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 compressor 6 is stopped so that only one compressor 6 is operating (S10). At this time, the automatic valve 8 provided in the line where the compressor 6 was stopped is also closed (S10).
[0059] Subsequently, the flow rate of the liquefied gas filled into the filling tank 3 is measured by a flow rate measuring means provided in the filling tank 3 (S11). In S11, when the liquid volume in the filling tank 3 reaches 90% by volume, all operating compressors 6 are sequentially stopped (S12), and the automatic valves 8 provided in the lines where the compressors 6 were stopped are closed to complete the filling process. In this way, by gradually stopping the compressor 6, which operates 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. Furthermore, this stabilizes the temperature and pressure inside the filling tank 3, preventing pressure fluctuations after filling.
[0060] [Second Embodiment] A method for filling with liquefied gas according to a second embodiment of the present invention will be described in detail with reference to Figures 4A to 4C. Note that only the differences between the method for filling with liquefied gas according to the second embodiment and the method for filling with liquefied gas 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 brought to an equal 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 brought to the same pressure, the storage tank 2 can be pressurized, and for example, if the liquefied gas is liquefied carbon dioxide, it is possible to prevent it from turning into dry ice due to a pressure drop.
[0063] In the liquefied gas filling method of the second embodiment, the supply line cooling process and the filling process are the same as in the liquefied gas filling method of the first embodiment, and the information provided for the liquefied gas filling method of the first embodiment can be applied.
[0064] In the liquefied gas filling method of the present invention, the starting and stopping of the compressor 6 and the opening and closing of the automatic valve 8 can be controlled by a control device (not shown).
[0065] While the present invention has been described based on the drawings, it should be noted that those skilled in the art will find it easy to make various modifications and alterations based on this disclosure. Therefore, it should be noted that these modifications and alterations are within the scope of the present invention. For example, the functions included in each component, each process, etc., can be rearranged in a logically consistent manner, and multiple components or processes can be combined into one or divided. [Industrial applicability]
[0066] According to the present invention, even when filling large tanks with liquefied gas, the occurrence of the water hammer phenomenon can be suppressed, and a liquefied gas filling system and method that can efficiently fill large quantities of liquefied gas can be provided. [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 equalization line
Claims
1. A storage tank for storing liquefied gas, A filling tank for filling with liquefied gas, A supply line connected to the storage tank and the filling tank, which supplies liquefied gas from the storage tank to the filling tank, One or more bypass lines connected to the supply line, The supply line and each of the one or more bypass lines are provided with a compressor for discharging the liquefied gas, The one or more bypass lines are connected in the supply line, with one end connected to the inlet side of the compressor provided in the supply line and the other end connected to the outlet side of the compressor provided in the supply line. A liquefied gas filling system in which the maximum amount of liquefied gas to be filled from the storage tank to the filling tank is 100 tons / hr or more.
2. The liquefied gas filling system according to claim 1, wherein the supply line has a fluid density measuring means between the connection portion of the supply line and the bypass line at the outlet side of the compressor provided in the supply line and the filling tank.
3. The liquefied gas filling system according to claim 1 or 2, wherein the filling tank has a liquid volume measuring means for measuring the liquid volume of the filled liquefied gas.
4. The liquefied gas filling system according to claim 1 or 2, 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 filling tank with liquefied gas, comprising filling a filling tank from a storage tank with liquefied gas through a supply line and one or more bypass lines connected to the supply line, A supply line cooling step involves supplying liquefied gas from the storage tank through the supply line connected to the filling tank and cooling the supply line, A filling step includes operating a compressor for dispensing the liquefied gas provided in the supply line and at least one of the compressors for dispensing the liquefied gas provided in one or more bypass lines, and filling the filling tank from the storage tank through the supply line and one or more bypass lines connected to the supply line, A method for filling a liquefied gas, wherein the maximum amount of liquefied gas to be filled from the storage tank to the filling tank is 100 tons / hr or more.
6. The method for filling a liquefied gas according to claim 5, further comprising a pressure equalization step of equalizing the pressure of the storage tank and the filling tank through a pressure equalization line connected to the storage tank and the filling tank, prior to the supply line cooling step.
7. A method for filling liquefied gas according to claim 5 or 6, wherein in the supply line cooling step, when the flow rate of 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 activated to increase the flow rate.
8. A method for filling liquefied gas according to claim 5 or 6, wherein in the filling step, after confirming that the liquefied gas in the supply line is of liquid density by a fluid density measuring means provided between the connection portion 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 filling tank with liquefied gas from the storage tank.
9. A method for filling liquefied gas according to claim 8, wherein when the amount of liquid in the filling tank, as measured by a liquid volume measuring means provided in the filling tank, reaches 80% by volume or more, the compressors provided in one or more bypass lines are sequentially stopped.
10. The method for filling a liquefied gas according to claim 8, wherein all compressors are stopped when the liquid volume in the filling tank reaches 90% by volume or more.