Liquefied Gas Monitoring System

Abstract

To provide a liquefied gas monitoring system capable of accurately grasping the amount of mixed liquefied gas and the environmental value.SOLUTION: A liquefied gas monitoring system 1 includes a container 2 that stores a liquefied gas 9 obtained by liquefying a single component gas, a liquid level sensor 31 that detects a liquid level in the container 2, and a controller 4 into which an environmental value of the liquefied gas 9 supplied each time the liquefied gas 9 is supplied into the container 2 is input. Before the liquefied gas 9 is supplied to the container 2, the controller 4 determines the amount of the previously supplied liquefied gas 9 remaining in the container 2 based on the liquid level detected by the liquid level sensor 31, and stores the amount together with the environmental value. Further, after the liquefied gas is supplied to the container 2, the controller 4 determines the amount of the liquefied gas 9 supplied this time based on the liquid level detected by the liquid level sensor 31, and records it together with the environmental value.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a liquefied gas monitoring system. [Background technology]

[0002] Liquefied gases, which are gases made by liquefying single-component gases, have traditionally been traded. Examples of single-component gases include hydrogen, ammonia, and methane. A common method for liquefying gas is to cool the gas and condense it. Alternatively, organic hydrides (e.g., methylcyclohexane), which are compounds of benzene or naphthalene with hydrogen that can be reversibly released, are liquid at room temperature and pressure, and can be used as liquefied gases. In other words, when organic hydrides are used, hydrogen is liquefied by combining hydrogen with a carrier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-86503 Summary of the Invention [Problem to be solved by the invention]

[0004] During the distribution process, liquefied gas may be mixed with other liquefied gases of the same type within a container. However, even if the liquefied gas is the same type, the environmental value of the liquefied gas varies depending on factors such as the production method. For this reason, when liquefied gases with different environmental values ​​are mixed within a container, the environmental value of the liquefied gas changes. In electricity trading, in addition to the trading of the electricity itself, environmental value is also a subject of trading. It is expected that the same will apply to liquefied gas trading in the future. Therefore, when liquefied gases with different environmental values ​​are mixed and distributed, it is necessary to calculate the environmental value after mixing in order to ensure the reliability of the transaction.

[0005] Here, the "environmental value of liquefied gas" refers to the economic value that indicates the extent to which the production of a single-component gas contributes to reducing the environmental impact. For example, if the amount of carbon dioxide emitted during the production of a single-component gas is small, the environmental value will be high. Note that when a single-component gas is produced by the chemical bonding of different components (for example, ammonia is produced by the chemical bonding of hydrogen and nitrogen), the amount of carbon dioxide emitted during the production of those components is also reflected in the environmental value.

[0006] In order to properly calculate the environmental value of the liquefied gas after mixing as described above, it is necessary to accurately grasp the amount and environmental value of the liquefied gas to be mixed. Note that Patent Document 1 describes a hydrogen gas supply system that supplies users with hydrogen gas as fuel, in which hydrogen gases with different environmental values ​​are mixed in a hydrogen gas container, and the environmental values ​​of the hydrogen gases and the mixed hydrogen gas are displayed separately on a display device, but the technology described in Patent Document 1 does not address the issue of mixing liquefied gases as described above.

[0007] Therefore, an object of the present disclosure is to provide a liquefied gas monitoring system that can accurately grasp the amount and environmental value of liquefied gas being mixed. [Means for solving the problem]

[0008] The present disclosure provides a liquefied gas monitoring system comprising: a container for storing liquefied gas obtained by liquefying a single-component gas; a liquid level sensor for detecting the liquid level in the container; and a controller into which the environmental value of the liquefied gas supplied each time liquefied gas is supplied to the container is input, wherein before liquefied gas is supplied to the container, the controller determines the amount of liquefied gas remaining in the container from the previous supply based on the liquid level detected by the liquid level sensor and records this together with the environmental value, and after liquefied gas is supplied to the container, the controller determines the amount of liquefied gas supplied this time based on the liquid level detected by the liquid level sensor and records this together with the environmental value. [Effects of the Invention]

[0009] According to the present disclosure, the amount and environmental value of the liquefied gas to be mixed can be accurately determined. [Brief explanation of the drawings]

[0010] [Figure 1A] FIG. 1 illustrates a state before the first loading of cargo onto a ship equipped with a liquefied gas monitoring system according to an embodiment. [Figure 1B] FIG. 2 shows the vessel after the first loading. [Figure 2A] FIG. 2 is a diagram showing a state before unloading from the ship. [Figure 2B] FIG. 2 is a diagram showing the state after unloading from the ship. [Figure 3A] FIG. 2 shows the vessel before the second loading. [Figure 3B] FIG. 10 shows the vessel after a second loading. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1A to 3B show a liquefied gas monitoring system 1 according to one embodiment. In this embodiment, the liquefied gas monitoring system 1 is mounted on a ship 5. However, the liquefied gas monitoring system 1 may also be mounted on a fixed facility such as an offshore facility or a land facility, or on a mobile object that moves on land or in the air (for example, a tank truck, a railroad car, an airplane, etc.).

[0012] 1A and 1B are diagrams for explaining the initial loading of cargo onto a ship 5, with FIG. 1A showing the state before loading and FIG. 1B showing the state after loading.

[0013] The liquefied gas monitoring system 1 includes a container 2 that stores liquefied gas 9, which is a liquefied single-component gas. The single-component gas is, for example, hydrogen, ammonia, methane, etc. The liquefied gas 9 may contain almost no impurities or may contain a certain amount of impurities (for example, 10 mass percent or less).

[0014] In this embodiment, before the first loading, liquefied gas 9A having environmental value Xa is stored in the container 2. That is, before the first loading, liquefied gas 9A is supplied to the container 2. The gas layer above the liquid level of the liquefied gas 9A in the container 2 is filled with vaporized gas obtained by vaporizing the liquefied gas 9A.

[0015] The liquefied gas monitoring system 1 also includes a liquid level sensor 31 that detects the liquid level in the container 2, and a controller 4 that is electrically connected to the liquid level sensor 31. The liquid level sensor 31 may be any type of sensor, such as a float type, a differential pressure type, an ultrasonic type, or a laser type.

[0016] In this embodiment, the controller 4 is also electrically connected to the pressure sensor 32 and the temperature sensor 33. However, in all drawings, the connection lines are omitted for simplicity. The pressure sensor 32 detects the pressure of the gas layer in the container 2, and the temperature sensor 33 detects the temperature of the gas layer in the container 2. However, the temperature sensor 33 may also detect the temperature of the liquefied gas 9 in the container 2.

[0017] The controller 4 is also electrically connected to the display 41. Every time liquefied gas 9 is supplied to the container 2, the environmental value X of the liquefied gas 9 is input into the controller 4. As described above, before the first loading, liquefied gas 9A is supplied to the container 2, and therefore the environmental value Xa of the liquefied gas 9A is input into the controller 4.

[0018] With respect to controller 4 (as well as controllers 62, 72, and 82 described below), the functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0019] In this embodiment, the initial loading onto the ship 5 is carried out between the ship 5 and the onshore facility 6. The onshore facility 6 includes a container 60 for storing the liquefied gas 9, a liquid level sensor 61 for detecting the liquid level in the container 60, and a controller 62 electrically connected to the liquid level sensor 61.

[0020] However, loading onto the vessel 5 may take place between the vessel 5 and an offshore facility. Alternatively, loading onto the vessel 5 may take place between the vessel 5 and another vessel.

[0021] In this embodiment, liquefied gas 9B having an environmental value Xb is stored in container 60. The environmental value Xb of liquefied gas 9B may be the same as or different from the environmental value Xa of liquefied gas 9A. The gas layer above the liquid surface of liquefied gas 9B in container 60 is filled with vaporized gas obtained by vaporizing liquefied gas 9B.

[0022] For the initial loading onto the vessel 5, the vessel 5 is moored at a quay near the onshore facility 6 as shown in Figure 1A, and then the vessel 2 on the vessel 5 and the vessel 60 on the onshore facility 6 are connected by a liquid pipeline 63 and a gas pipeline 64 as shown in Figure 1B.

[0023] One end of the liquid pipeline 63 is a fixed pipe provided on the ship 5, and the other end is a fixed pipe provided on the land facility 6. The middle part of the liquid pipeline 63 is made up of a loading arm installed on the quay. In Fig. 1A, the liquid pipeline 63 is not shown to simplify the drawing.

[0024] Similarly, one end of the gas pipeline 64 is a fixed pipe provided on the ship 5, and the other end is a fixed pipe provided on the onshore facility 6. The middle part of the gas pipeline 64 is composed of a loading arm installed on the quay. In Fig. 1A, the gas pipeline 64 is not shown in order to simplify the drawing.

[0025] 1B, for the sake of simplicity, the liquid pipeline 63 is drawn below the vessels 2 and 60, and the gas pipeline 64 is drawn above the vessels 2 and 60, but the actual routes and opening positions of the liquid pipeline 63 and the gas pipeline 64 may be determined appropriately. For example, a dome may be provided on the top of the vessel 2 of the ship 5, and one end of the liquid pipeline 63 and the gas pipeline 64 may pass through the dome.

[0026] After the connection via the liquid pipeline 63 and the gas pipeline 64 is completed, liquefied gas 9B is supplied from the container 60 of the onshore facility 6 to the container 2 of the ship 5 through the liquid pipeline 63, and vaporized gas is supplied from the gas space in the container 2 to the gas space in the container 60 through the gas pipeline 64.

[0027] Before liquefied gas 9B is supplied to container 2, controller 4 determines the amount Ya of liquefied gas 9A that was supplied previously and remains in container 2, based on the liquid level L1 detected by liquid level sensor 31, the pressure P detected by pressure sensor 32, and the temperature T detected by temperature sensor 33, and records the determined amount Ya of liquefied gas 9A together with the environmental value Xa. The unit of the amount Ya is, for example, kg (the same applies to amount Yb, etc., described below). During the first loading, only the liquefied gas 9A that was supplied previously remains in container 2, so controller 4 calculates the amount Ya of liquefied gas 9A by multiplying the volume inside container 2 below liquid level L1 detected by liquid level sensor 31 by the density of liquefied gas 9A at pressure P and temperature T.

[0028] It should be noted that since liquefied gas 9A is simply liquefied gas 9 identified by environmental value X, the density of liquefied gas 9A is the same as the density of liquefied gas 9. This also applies to liquefied gas 9B and liquefied gases 9C and 9D, which will be described later.

[0029] For example, when the liquefied gas 9 is liquefied hydrogen, the density at the saturation temperature (-253°C) when the pressure is atmospheric pressure (approximately 0.1 MPa) is 71 kg / m 3 However, when the pressure changes to 1.0 MPa (saturation temperature -242°C), the density becomes 50 kg / m 3 The controller 4 stores in advance a physical property table or a relational expression that indicates the relationship between the pressure and temperature and the density of the liquefied gas 9, and the controller 4 determines the density of the liquefied gas 9 using the physical property table or the relational expression.

[0030] Before, during, or after loading, the environmental value Xb of the liquefied gas 9B to be supplied to the container 2 is input to the controller 4. If the environmental value Xb of the liquefied gas 9B is pre-stored in the controller 62, the input of this environmental value Xb may be performed by wireless communication from the controller 62 to the controller 4, or may be performed manually by an operator via an input device electrically connected to the controller 4.

[0031] After liquefied gas 9B has been supplied to container 2, controller 4 determines the amount Yb of liquefied gas 9B supplied this time based on the liquid level L2 measured by liquid level sensor 31, the pressure P detected by pressure sensor 32, and the temperature T detected by temperature sensor 33, and records the determined amount Yb of liquefied gas 9B together with the environmental value Xb. Specifically, controller 4 calculates the amount Yb of liquefied gas 9B by multiplying the volume inside container 2 between the liquid level L1 before loading and the liquid level L2 after loading by the density of liquefied gas 9 at the pressure P and temperature T.

[0032] Before liquefied gas 9B is supplied, the only liquefied gas 9 remaining in container 2 is the previously supplied liquefied gas 9A. Therefore, if the amount Ya and environmental value Xa of liquefied gas 9A supplied previously and the amount Yb and environmental value Xb of liquefied gas 9B supplied this time are recorded, then by referring to this data, it is possible to accurately determine the amounts Ya and Yb of liquefied gases 9A and 9B to be mixed and the environmental values ​​Xa and Xb.

[0033] After the liquefied gas 9B has been supplied to the container 2, the controller 4 simultaneously displays the amount Ya and environmental value Xa of the liquefied gas 9A supplied previously, and the amount Yb and environmental value Xb of the liquefied gas 9B supplied this time on the display 41. This makes it possible to visually grasp the amounts Ya and Yb of the liquefied gases 9A and 9B to be mixed, and the environmental values ​​Xa and Xb.

[0034] 2A and 2B are diagrams for explaining unloading from the ship 5, with FIG. 2A showing the state before unloading and FIG. 2B showing the state after unloading.

[0035] In this embodiment, unloading from the ship 5 is performed between the ship 5 and the onshore facility 7. The onshore facility 7 includes a container 70 for storing liquefied gas 9, a liquid level sensor 71 for detecting the liquid level in the container 70, and a controller 72 electrically connected to the liquid level sensor 71.

[0036] However, the discharge from the vessel 5 may be carried out between the vessel 5 and the offshore facility. Alternatively, the discharge from the vessel 5 may be carried out between the vessel 5 and another vessel.

[0037] In this embodiment, liquefied gas 9C having an environmental value Xc is stored in container 70. Note that the environmental value Xc of liquefied gas 9C may be the same as the environmental value Xa of liquefied gas 9A or the environmental value Xb of liquefied gas 9B, or may be different from both the environmental value Xa of liquefied gas 9A and the environmental value Xb of liquefied gas 9B. The gas layer above the liquid surface of liquefied gas 9C in container 70 is filled with vaporized gas obtained by vaporizing liquefied gas 9C.

[0038] When unloading from the vessel 5, the vessel 5 is moored to a quay near the onshore facility 7 as shown in Figure 2A, and then the vessel 2 on the vessel 5 and the vessel 70 on the onshore facility 7 are connected by a liquid pipeline 73 and a gas pipeline 74 as shown in Figure 2B.

[0039] One end of the liquid pipeline 73 is a fixed pipe provided on the ship 5, and the other end is a fixed pipe provided on the onshore facility 7. The middle part of the liquid pipeline 73 is made up of a loading arm installed on the quay. In Fig. 2A, the liquid pipeline 73 is not shown to simplify the drawing.

[0040] Similarly, one end of the gas pipeline 74 is a fixed pipe provided on the ship 5, and the other end is a fixed pipe provided on the onshore facility 7. The middle part of the gas pipeline 74 is composed of a loading arm installed on the quay. In Fig. 2A, the gas pipeline 74 is not shown in order to simplify the drawing.

[0041] In Figure 2B, for the sake of simplicity, the liquid pipeline 73 is drawn below the vessels 2, 70 and the gas pipeline 74 is drawn above the vessels 2, 70, but as with the liquid pipeline 63 and gas pipeline 64 of the onshore facility 6, the actual routes and opening positions of the liquid pipeline 73 and gas pipeline 74 will be determined appropriately.

[0042] After the connection via liquid pipeline 73 and gas pipeline 74 is completed, liquefied gas 9, a mixture of liquefied gas 9A and liquefied gas 9B, is discharged from container 2 of ship 5 to container 70 of onshore facility 7 through liquid pipeline 73, and vaporized gas is supplied from the gas space in container 70 to the gas space in container 2 through gas pipeline 74.

[0043] Before the liquefied gas 9 in the container 2 is dispensed, the controller 4 determines the amounts Ya1, Yb1 of the liquefied gas 9A, 9B that are present in the container 2 and that have been supplied at least twice in the most recent time, based on the liquid level L3 detected by the liquid level sensor 31, the pressure P detected by the pressure sensor 32, and the temperature T detected by the temperature sensor 33, and records the determined amounts Ya1, Yb1 of the liquefied gas 9A, 9B together with the environmental values ​​Xa, Xb. Specifically, the controller 4 multiplies the volume inside the container 2 below the liquid level L3 detected by the liquid level sensor 31 by the density of the liquefied gas 9 at the pressure P and temperature T to calculate the total amount Y of the liquefied gas 9, and then multiplies the total amount Y by the ratio (Ya / (Ya+Yb) and Yb / (Ya+Yb)) of the amounts Ya, Yb recorded after the previous liquefied gas supply to calculate the amounts Ya1, Yb1 of the liquefied gas 9A, 9B.

[0044] The majority of the liquefied gas 9 present in the container 2 before the liquefied gas 9 is dispensed (all of it in the case of the first unloading) is the liquefied gases 9A and 9B that were supplied in the two most recent times. Therefore, if the amounts Ya1 and Yb1 of the liquefied gases 9A and 9B and the environmental values ​​Xa and Xb that were supplied at least in the two most recent times before the liquefied gas 9 is dispensed are recorded, then by comparing this data with the data recorded after the immediately preceding liquefied gas supply, it is possible to determine the amount and environmental value of the liquefied gas 9 that was consumed as boil-off gas before the liquefied gas 9 was dispensed.

[0045] After the liquefied gas 9 in the container 2 has been dispensed, the controller 4 determines the amounts Ya2 and Yb2 of the liquefied gas 9A and 9B remaining in the container 2 that were supplied at least twice in the most recent supply based on the liquid level L4 detected by the liquid level sensor 31, the pressure P detected by the pressure sensor 32, and the temperature T detected by the temperature sensor 33, and records the determined amounts Ya2 and Yb2 of the liquefied gas 9A and 9B together with the environmental values ​​Xa and Xb. Specifically, the controller 4 multiplies the volume inside the container 2 below the liquid level L4 detected by the liquid level sensor 31 by the density of the liquefied gas 9 at the pressure P and temperature T to calculate the total amount Y of the liquefied gas 9, and then multiplies the total amount Y by the ratio (Ya / (Ya+Yb) and Yb / (Ya+Yb)) of the amounts Ya and Yb recorded after the most recent supply of liquefied gas to calculate the amounts Ya2 and Yb2 of the liquefied gas 9A and 9B.

[0046] In this way, even after the liquefied gas 9 has been dispensed, the amounts Ya2, Yb2 of the liquefied gas 9A, 9B supplied at least twice in the past and the environmental values ​​Xa, Xb are recorded, and by referring to this data, it is possible to determine the amounts Ya2, Yb2 of the liquefied gas 9A, 9B supplied at least twice in the past and the environmental values ​​Xa, Xb remaining in the container 2.

[0047] Furthermore, container 2 from Liquefied gas 9B Payout After this, the controller 4 simultaneously displays the amounts Ya2, Yb2 of the liquefied gas 9A, 9B that have been supplied at least twice most recently and that remain in the container 2, and the environmental values ​​Xa, Xb, on the display 41. This makes it possible to visually grasp the amounts Ya2, Yb2 of the liquefied gas 9A, 9B that have been supplied at least twice most recently and that remain in the container 2, and the environmental values ​​Xa, Xb.

[0048] When the liquefied gas 9 in the container 2 is dispensed, the environmental value Xg of the vaporized gas to be supplied to the gas layer in the container 2 is input to the controller 4. This input of the environmental value Xg may be performed by wireless communication from the controller 72 to the controller 4 if the environmental value Xg of the vaporized gas is pre-stored in the controller 72, or may be performed manually by an operator via an input device electrically connected to the controller 4.

[0049] As described above, the gas space in the container 70 of the onshore facility 7 is filled with the vaporized gas obtained by vaporizing the liquefied gas 9C, so the environmental value Xg of the vaporized gas supplied to the gas space in the container 2 is the same as the environmental value Xc of the liquefied gas 9C. 70 If liquefied gases with different environmental values ​​are mixed in the container, 70 The environmental value Xg of the vaporized gas supplied from the container 2 to the container 2 may be calculated based on the mixture ratio of the liquefied gas, etc.

[0050] After the liquefied gas 9 in the container 2 is dispensed, the controller 4 records the amount Yg of vaporized gas supplied to the gas layer in the container 2 together with the environmental value Xg. This makes it possible to manage not only the amount and environmental value of the liquefied gas 9 but also the amount and environmental value of the vaporized gas.

[0051] The amount Yg of vaporized gas supplied to the gas layer in container 2 can be calculated, for example, by integrating the flow rate of vaporized gas flowing through gas pipe 74. Alternatively, the amount Yg of vaporized gas may be calculated by multiplying the volume inside container 2 between the liquid level height L3 before unloading and the liquid level height L4 after unloading by the density of the vaporized gas at the pressure P detected by pressure sensor 32 and the temperature T detected by temperature sensor 33.

[0052] 3A and 3B are diagrams for explaining the second loading of cargo onto the ship 5, with FIG. 3A showing the state before loading and FIG. 3B showing the state after loading.

[0053] In this embodiment, the second loading onto the ship 5 is carried out between the ship 5 and the onshore facility 8. The onshore facility 8 includes a container 80 for storing liquefied gas 9, a liquid level sensor 81 for detecting the liquid level in the container 80, and a controller 82 electrically connected to the liquid level sensor 81. Note that the onshore facility 8 may be the same as or different from the onshore facility 6 where the first loading was carried out.

[0054] However, loading onto the vessel 5 may take place between the vessel 5 and an offshore facility. Alternatively, loading onto the vessel 5 may take place between the vessel 5 and another vessel.

[0055] In this embodiment, liquefied gas 9D having an environmental value Xd is stored in container 80. Note that the environmental value Xd of liquefied gas 9D may be the same as the environmental value Xa of liquefied gas 9A, the environmental value Xb of liquefied gas 9B, or the environmental value Xc of liquefied gas 9C, or may be different from the environmental value Xa of liquefied gas 9A, the environmental value Xb of liquefied gas 9B, or the environmental value Xc of liquefied gas 9C. The gas layer above the liquid level of liquefied gas 9D in container 80 is filled with vaporized gas obtained by vaporizing liquefied gas 9D.

[0056] For the second loading onto the vessel 5, the vessel 5 is moored at a quay near the onshore facility 8 as shown in Figure 3A, and then the vessel 2 on the vessel 5 and the vessel 80 on the onshore facility 8 are connected by a liquid pipeline 83 and a gas pipeline 84 as shown in Figure 3B.

[0057] One end of the liquid pipeline 83 is a fixed pipe installed on the ship 5, and the other end is a fixed pipe installed on the land facility 8. The middle part of the liquid pipeline 83 is made up of a loading arm installed on the quay. 3 In A, the liquid pipeline 83 is omitted for the sake of simplicity.

[0058] Similarly, one end of the gas pipeline 84 is a fixed pipe installed on the ship 5, and the other end is a fixed pipe installed on the land facility 8. The middle part of the gas pipeline 84 is composed of a loading arm installed on the quay. 3In A, the gas pipeline 84 is not shown to simplify the drawing.

[0059] In Figure 3B, for the sake of simplicity, the liquid pipeline 83 is drawn below the vessels 2, 80 and the gas pipeline 84 is drawn above the vessels 2, 80, but as with the liquid pipeline 63 and gas pipeline 64 of the onshore facility 6, the actual routes and opening positions of the liquid pipeline 83 and gas pipeline 84 will be determined appropriately.

[0060] After the connection via liquid pipeline 83 and gas pipeline 84 is completed, liquefied gas 9D is supplied from container 80 of land-based facility 8 to container 2 of ship 5 through liquid pipeline 83, and vaporized gas is supplied from the gas space in container 2 to the gas space in container 80 through gas pipeline 84.

[0061] Before liquefied gas 9D is supplied to container 2, controller 4 determines the amount Yb3 of liquefied gas 9B that was supplied previously and remains in container 2 based on the liquid level height L5 detected by liquid level sensor 31, the pressure P detected by pressure sensor 32, and the temperature T detected by temperature sensor 33, and records the determined amount Yb3 of liquefied gas 9B together with the environmental value Xb. Specifically, controller 4 multiplies the volume inside container 2 below the liquid level height L5 detected by liquid level sensor 31 by the density of liquefied gas 9 at pressure P and temperature T to calculate the total amount Y of liquefied gas 9, and then multiplies this total amount Y by the ratio (Yb / (Ya+Yb)) of the amount Yb recorded after the previous supply of liquefied gas to calculate the amount Yb3 of liquefied gas 9B.

[0062] Before, during, or after loading, the environmental value Xd of the liquefied gas 9D to be supplied to the container 2 is input to the controller 4. If the environmental value Xd of the liquefied gas 9D is pre-stored in the controller 82, the input of this environmental value Xd may be performed by wireless communication from the controller 82 to the controller 4, or may be performed manually by an operator via an input device electrically connected to the controller 4.

[0063] After the liquefied gas 9D has been supplied to the container 2, the controller 4 determines the amount Yd of the liquefied gas 9D supplied this time based on the liquid level L6 measured by the liquid level sensor 31, the pressure P detected by the pressure sensor 32, and the temperature T detected by the temperature sensor 33, and records the determined amount Yd of the liquefied gas 9D together with the environmental value Xd. Specifically, the controller 4 calculates the amount Yd of the liquefied gas 9D by multiplying the volume inside the container 2 between the liquid level L5 before loading and the liquid level L6 after loading by the density of the liquefied gas 9 at the pressure P and temperature T.

[0064] The liquefied gas 9 remaining in the container 2 before the liquefied gas 9D is supplied contains a large amount of the liquefied gas 9B that was supplied previously. Therefore, if the amount Yb3 and environmental value Xb of the liquefied gas 9B that was supplied previously and the amount Yd and environmental value Xd of the liquefied gas 9D that is being supplied this time are recorded, then by referring to this data it is possible to accurately determine the amounts Yb3, Yd of the liquefied gases 9B and 9D to be mixed and the environmental values ​​Xb, Xd. Moreover, by referring to past data it is possible to track the mixing history of the liquefied gas 9.

[0065] (Variation) The present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present disclosure.

[0066] For example, if the pressure and temperature of the gas layer of the liquefied gas 9 in the container 2 are kept substantially constant, when loading onto the ship 5, the controller 4 determines the amount of the previously supplied liquefied gas (9A or 9B) remaining in the container 2 before the liquefied gas 9 is supplied based only on the liquid level (L1, L2, L5 or L6) detected by the liquid level sensor 31, and then supplies the liquefied gas 9 to the container 2. 9 After the supply of the liquefied gas (9B or 9D), the amount of the liquefied gas supplied this time (9B or 9D) may be determined. In this case, when unloading from the ship 5, the controller 4 determines the amount of the liquefied gas in the container 2 based only on the liquid level (L3 or L4) detected by the liquid level sensor 31. 9Before the liquefied gas 9 in the container 2 is dispensed, the amount of liquefied gas 9A, 9B that has been supplied at least twice in the last two times and that is present in the container 2 may be determined, and after the liquefied gas 9 in the container 2 is dispensed, the amount of liquefied gas 9A, 9B that has been supplied at least twice in the last two times and that remains in the container 2 may be determined.

[0067] However, if the amount of liquefied gas is determined based not only on the liquid level detected by the liquid level sensor 31 as in the above embodiment, but also on the pressure P detected by the pressure sensor 32 and the temperature T detected by the temperature sensor 33, the amount of liquefied gas can be accurately determined.

[0068] (summary) The present disclosure provides a liquefied gas monitoring system comprising: a container for storing liquefied gas obtained by liquefying a single-component gas; a liquid level sensor for detecting the liquid level in the container; and a controller into which the environmental value of the liquefied gas supplied each time liquefied gas is supplied to the container is input, wherein before liquefied gas is supplied to the container, the controller determines the amount of liquefied gas remaining in the container from the previous supply based on the liquid level detected by the liquid level sensor and records this together with the environmental value, and after liquefied gas is supplied to the container, the controller determines the amount of liquefied gas supplied this time based on the liquid level detected by the liquid level sensor and records this together with the environmental value.

[0069] The liquefied gas remaining in a container before the liquefied gas is supplied contains a large amount of the liquefied gas supplied previously. Therefore, if the amount and environmental value of the liquefied gas supplied previously and the amount and environmental value of the liquefied gas supplied this time are recorded, the amount and environmental value of the liquefied gas to be mixed can be accurately determined by referring to that data. Moreover, by referring to past data, the mixing history of the liquefied gas can be tracked.

[0070] The liquefied gas monitoring system may include a pressure sensor that detects the pressure of the gas layer in the container, and a temperature sensor that detects the temperature of the gas layer or the liquefied gas in the container, and the controller may determine the amount of liquefied gas remaining in the container from the previous supply based on not only the liquid level detected by the liquid level sensor but also the pressure detected by the pressure sensor and the temperature detected by the temperature sensor before the liquefied gas is supplied, and may determine the amount of liquefied gas currently supplied after the liquefied gas is supplied to the container. With this configuration, the amount of liquefied gas can be accurately determined.

[0071] After liquefied gas has been supplied to the container, the controller may cause a display to simultaneously display the amount and environmental value of the liquefied gas previously supplied and the amount and environmental value of the liquefied gas currently supplied. With this configuration, the amount and environmental value of the liquefied gas to be mixed can be visually grasped.

[0072] The controller may determine, before the liquefied gas in the container is dispensed, the amount of liquefied gas that has been supplied at least two times most recently and remains in the container based on the liquid level detected by the liquid level sensor, and record the amount together with the environmental value. After the liquefied gas in the container is dispensed, the controller may determine, based on the liquid level detected by the liquid level sensor, the amount of liquefied gas that has been supplied at least two times most recently and remains in the container, and record the amount together with the environmental value. Most of the liquefied gas remaining in the container before the liquefied gas is dispensed is the liquefied gas that has been supplied the two most recent times. Therefore, if the amount and environmental value of the liquefied gas that have been supplied at least two times most recently before the liquefied gas is dispensed are recorded, the amount and environmental value of the liquefied gas that has been consumed as boil-off gas before the liquefied gas is dispensed can be determined by comparing the data with data recorded after the immediately preceding liquefied gas supply. Furthermore, even after the liquefied gas is dispensed, the amount and environmental value of the liquefied gas supplied at least two times in the past are recorded, so by referring to this data, it is possible to determine the amount and environmental value of the liquefied gas remaining in the container at least two times in the past.

[0073] The apparatus may include a pressure sensor that detects the pressure of the gas layer in the container, and a temperature sensor that detects the temperature of the gas layer or the liquefied gas in the container, and the controller may determine the amount of liquefied gas that has been supplied at least two times most recently and remains in the container before the liquefied gas in the container is dispensed, based on not only the liquid level detected by the liquid level sensor but also the pressure detected by the pressure sensor and the temperature detected by the temperature sensor, and may determine the amount of liquefied gas that has been supplied at least two times most recently and remains in the container after the liquefied gas in the container has been dispensed. With this configuration, the amount of liquefied gas can be accurately determined.

[0074] After the liquefied gas in the container has been dispensed, the controller may cause a display to simultaneously display the amount of liquefied gas remaining in the container that has been supplied at least twice in the most recent time and the environmental value. With this configuration, the amount of liquefied gas remaining in the container that has been supplied at least twice in the most recent time and the environmental value can be visually grasped.

[0075] When the liquefied gas in the container is dispensed, the vaporized gas is supplied to the gas space in the container, and the environmental value of the vaporized gas is input to the controller, and the controller may record the amount of vaporized gas supplied to the gas space in the container together with the environmental value after the liquefied gas in the container is dispensed. With this configuration, it is possible to manage not only the amount and environmental value of the liquefied gas, but also the amount and environmental value of the vaporized gas. [Explanation of symbols]

[0076] 1. Liquefied Gas Monitoring System 2 containers 31 Liquid level sensor 32 Pressure Sensor 33 Temperature Sensor 4 Controller 41 Display 9, 9A~9D Liquefied gas

Claims

1. a container for storing liquefied gas obtained by liquefying a single-component gas; a liquid level sensor for detecting the liquid level in the container; a controller into which the environmental value of the supplied liquefied gas is input each time the liquefied gas is supplied to the container; The controller Before the liquefied gas is supplied to the container, the amount of the liquefied gas previously supplied remaining in the container is determined based on the liquid level detected by the liquid level sensor, and the amount is recorded together with the environmental value; A liquefied gas monitoring system that, after liquefied gas is supplied to the container, determines the amount of liquefied gas supplied this time based on the liquid level detected by the liquid level sensor and records the amount together with the environmental value.

2. a pressure sensor for detecting the pressure of the gas layer in the container; a temperature sensor for detecting the temperature of the gas layer or liquefied gas in the container; The liquefied gas monitoring system of claim 1, wherein the controller determines the amount of liquefied gas remaining in the container from the previous supply based on not only the liquid level detected by the liquid level sensor but also the pressure detected by the pressure sensor and the temperature detected by the temperature sensor before the liquefied gas is supplied, and determines the amount of liquefied gas supplied this time after the liquefied gas is supplied to the container.

3. A liquefied gas monitoring system as described in claim 1 or 2, wherein after liquefied gas is supplied to the container, the controller causes a display to simultaneously display the amount and environmental value of liquefied gas supplied previously and the amount and environmental value of liquefied gas supplied this time.

4. The controller Before the liquefied gas in the container is dispensed, the amount of liquefied gas in the container that has been supplied at least two times in the past is determined based on the liquid level detected by the liquid level sensor, and the amount is recorded together with the environmental value; A liquefied gas monitoring system as described in any one of claims 1 to 3, wherein after the liquefied gas in the container is dispensed, the amount of liquefied gas remaining in the container that was supplied at least two times in the most recent period is determined based on the liquid level detected by the liquid level sensor and recorded together with the environmental value.

5. a pressure sensor for detecting the pressure of the gas layer in the container; a temperature sensor for detecting the temperature of the gas layer or liquefied gas in the container; The liquefied gas monitoring system of claim 4, wherein the controller determines the amount of liquefied gas that has been supplied at least two times most recently and is present in the container before the liquefied gas in the container is dispensed based not only on the liquid level detected by the liquid level sensor but also on the pressure detected by the pressure sensor and the temperature detected by the temperature sensor, and determines the amount of liquefied gas that has been supplied at least two times most recently and remains in the container after the liquefied gas in the container has been dispensed.

6. A liquefied gas monitoring system as described in claim 4 or 5, wherein the controller causes a display to simultaneously display the amount of liquefied gas remaining in the container from at least the two most recent supplies and its environmental value after the liquefied gas in the container has been dispensed.

7. When the liquefied gas in the container is dispensed, a vaporized gas is supplied to the gas layer in the container, and the environmental value of the vaporized gas is input to the controller; A liquefied gas monitoring system as described in any one of claims 1 to 6, wherein the controller records the amount of vaporized gas supplied to the gas layer in the container together with the environmental value after the liquefied gas in the container is dispensed.

Images