JP5722186B2 - Liquefied gas supply method - Google Patents

Description

The present invention relates to a liquefied gas supply how, particularly, a method liquefied gas supply to use liquefied gas supply apparatus for a liquefied gas filled in a plurality of liquefied gas containers evaporated supplied to the gas-used About.

  As a liquefied gas supply method for evaporating the liquefied gas filled in a plurality of liquefied gas containers and supplying the liquefied gas to a gas user, a pressurizing means for increasing the pressure in the plurality of liquefied gas containers (bulk containers) is provided. In addition, the pressure in each liquefied gas container is monitored, gas is supplied from the first liquefied gas container having a relatively high pressure, and the gas is supplied when the pressure in the first liquefied gas container decreases. Is switched from the second liquefied gas container, and the first liquefied gas container whose pressure has been reduced is replaced to continuously supply the gas to the user of the gas (for example, , See Patent Document 1).

Japanese Patent Laid-Open No. 2007-231982

  However, as in Patent Document 1, in the case of LNG having a high vapor pressure near normal temperature, most of the LNG in the liquefied gas container can be evaporated and supplied. However, a gas having a low vapor pressure near normal temperature can be supplied. For example, in the case of liquefied ammonia, when the remaining amount of liquefied gas in the liquefied gas container becomes 30% or less of the volume of the container, the amount of evaporation gradually decreases, making it difficult to supply the gas at the flow rate required by the gas user. It becomes. For this reason, when the flow rate supplied to the gas user is relatively large, when the remaining amount of the liquefied gas in the liquefied gas container reaches about 30% of the container volume, the liquefied gas container to which the gas is supplied is switched and liquefied. By exchanging the liquefied gas container whose remaining amount of gas is reduced, a predetermined flow rate of gas can be continuously supplied to the gas user.

  Therefore, the liquefied ammonia filled in the liquefied gas container cannot be sufficiently used, and not only the utilization efficiency of the liquefied ammonia is lowered, but also the replacement cycle of the liquefied gas container is shortened. Further, by heating the liquefied gas container filled with liquefied ammonia to a high temperature to promote the evaporation of the liquefied ammonia, it is possible to evaporate most of the liquefied ammonia in the liquefied gas container while supplying the evaporated ammonia at a predetermined flow rate. Although it is possible, special heating equipment for heating a large bulk container to a high temperature is necessary, and there is a problem that equipment cost and running cost are significantly increased.

  Therefore, the present invention provides a liquefied gas supply device capable of increasing the utilization efficiency of a liquefied gas filled in a liquefied gas container with a simple apparatus configuration and procedure, particularly a liquefied gas having a low vapor pressure near room temperature such as liquefied ammonia. And to provide a method.

In order to achieve the above object, the first configuration of the liquefied gas supply method of the present invention uses a liquefied gas supply device that evaporates the liquefied gas filled in a plurality of liquefied gas containers and supplies it to a gas user. In the liquefied gas supply method, a liquefied gas container connected to each of a plurality of gas supply systems, a liquefied gas amount detection means for detecting the amount of liquefied gas in each liquefied gas container, and each gas supply system are provided. Pressure adjustment means for adjusting the pressure on the secondary side, gas supply shut-off means provided in each gas supply system, and the use of supplying gas supplied from multiple gas supply systems to the gas user Each gas supply system is preliminarily provided with a pressure on the secondary side of the pressure adjusting means based on the amount of liquefied gas in the liquefied gas container detected by the liquefied gas amount detecting means. Control to control one of a plurality of set pressures, and control to open / close the gas supply shut-off means provided in the gas supply system and the gas supply shut-off means provided in another gas supply system. A liquefied gas supply method for continuously supplying gas to the gas use destination using a liquefied gas supply device comprising means, wherein the control means is provided in a first gas supply system. The first liquefied gas is opened when gas supply from the first liquefied gas container is performed by opening the first gas supply blocking means and setting the secondary side set pressure of the first pressure adjusting means to the reference set pressure. When the liquefied gas amount in the first liquefied gas container detected by the amount detecting means falls below a preset first residual gas amount set value, the reference value is set as the secondary set pressure of the first pressure adjusting means. Higher than set pressure It sets the force line of the gas supply in parallel from both the first gas supply system and a second gas supply system by opening the second gas supply interrupting means provided in the second gas supply system The second liquefied gas amount in which the liquefied gas amount in the first liquefied gas container detected by the first liquefied gas amount detecting means is set to be smaller than the first residual gas amount set value. When the value falls below the set value, the first gas supply shut-off means is closed to stop the gas supply from the first gas supply system and switch to the gas supply from the second gas supply system .

The second configuration of the liquefied gas supply method of the present invention is a liquefied gas supply method that uses a liquefied gas supply device that evaporates the liquefied gas filled in a plurality of liquefied gas containers and supplies it to a gas user. The liquefied gas containers respectively connected to the plurality of gas supply systems, the liquefied gas amount detecting means for detecting the liquefied gas amounts in the respective liquefied gas containers, and the gas supply systems respectively provided on the secondary side. A pressure adjusting means for adjusting the pressure, a gas supply shut-off means provided in each gas supply system, a use gas supply path for supplying the gas supplied from a plurality of gas supply systems to the gas use destination, and Each gas supply system includes a plurality of settings in which the pressure on the secondary side of the pressure adjusting means is set in advance based on the amount of liquefied gas in the liquefied gas container detected by the liquefied gas amount detecting means. Control means for controlling the opening and closing of the gas supply cutoff means provided in the gas supply system and the gas supply cutoff means provided in another gas supply system, respectively, The pressure adjusting means continuously uses the liquefied gas supply device that is a pressure adjusting valve that adjusts the pressure on the secondary side by adjusting the flow passage area through which the gas flows with the opening of the valve. A liquefied gas supply method for supplying gas, wherein the control means opens a first gas supply shut-off means provided in a first gas supply system, and sets the secondary side set pressure of the first pressure regulating valve. When the gas is supplied from the first liquefied gas container with the pressure set to the reference set pressure, the amount of liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detecting means is preset. First remaining gas amount setting When the value falls below the value, the first pressure regulating valve is fully opened, and the second gas supply blocking means provided in the second gas supply system is opened to open the first gas supply system and the second gas supply system. from both the gas supply system have rows of gas supply in parallel, liquefied gas of said first liquefied gas container detected by said first liquefied gas amount detection means, the first residual gas amount set value When the second residual gas amount set value set to a smaller liquefied gas amount falls below, the first gas supply shut-off means is closed to stop the gas supply from the first gas supply system, and the second gas It is characterized by switching to gas supply from a supply system .

  According to the present invention, a plurality of gas supply systems can be continuously supplied to a gas user by switching based on the amount of liquefied gas in a liquefied gas container connected to each gas supply system, By controlling the set pressure on the secondary side of the pressure adjusting means by the control means that operates based on the liquefied gas amount detected by the liquefied gas amount detecting means, or by fully opening the pressure adjusting valve, the amount of liquefied gas can be reduced. The reduced liquefied gas in the liquefied gas container can be supplied to the gas user. Thereby, while the utilization efficiency of liquefied gas can be improved, the replacement | exchange period of a liquefied gas container can be lengthened.

It is a systematic diagram which shows one example of the liquefied gas supply apparatus of this invention. It is a flowchart which shows the 1st form example of the liquefied gas supply method of this invention. It is explanatory drawing which shows the change of the residual gas rate in the liquefied gas container in the 1st example of a method of this invention, the supply pressure, a flow volume, and the state of a pressure regulating valve. It is a flowchart which shows the 2nd form example of the liquefied gas supply method of this invention. It is explanatory drawing which shows the change of the residual gas rate in the liquefied gas container in the 2nd example of a method of this invention, the supply pressure, a flow volume, and the state of a pressure regulating valve in the gas supply.

  First, as shown in FIG. 1, the liquefied gas supply apparatus shown in the present embodiment supplies liquefied ammonia by evaporation, and a plurality of gas supply systems A and B in this embodiment are provided. And liquefied gas containers 11a and 11b connected to the gas supply systems A and B, respectively, and a weigh scale 12a as a liquefied gas amount detecting means for detecting the amount of liquefied gas in each of the liquefied gas containers 11a and 11b. , 12b, pressure indicating controllers (PIC) 13a, 13b as pressure adjusting means provided in each gas supply system A system, B system, respectively, for adjusting the pressure on the secondary side to the indicated pressure, and each gas Automatic on-off valves 14a and 14b, which are provided in the supply systems A and B, respectively, as gas supply shut-off means for supplying and stopping the gas, and the gases supplied from the gas supply systems A and B are combined. Gas use The pressure indicating controllers 13a and 13b and the automatic opening / closing valve 14a based on the remaining amount of the liquefied gas in the liquefied gas containers 11a and 11b detected by the weighing scales 12a and 12b. , 14b. Further, the use gas supply path 15 shown in this embodiment includes a pressure regulator 17 for adjusting the pressure of the gas supplied to the gas use to a preset pressure.

  The pressure indicating controllers 13a and 13b include valve portions 18a and 18b for adjusting the flow passage area through which the gas flows with the opening of the valve, and pressure detecting portions 19a and 19b for detecting the secondary pressure. The pressure adjustment by the pressure indicating controllers 13a and 13b is performed based on the pressure instructed by the control means 16 and the pressure detected by the pressure detectors 19a and 19b, and is detected by the pressure detectors 19a and 19b. The valve openings of the valve portions 18a and 18b are controlled so that the pressure thus obtained matches the pressure instructed by the control means 16.

  When gas is supplied from the liquefied gas containers 11a and 11b of the gas supply systems A and B, the preset pressure is instructed to the pressure indicating controllers 13a and 13b, and the automatic open / close valves 14a and 14b are opened. Thus, when the gas supply is stopped, the automatic open / close valves 14a and 14b are closed. The liquefied gas containers 11a and 11b are replaced when the automatic open / close valves 14a and 14b are closed. After the liquefied gas container is replaced, gas supply is performed until the control means 16 opens the automatic open / close valves 14a and 14b. It will be in a standby state without performing.

  Hereinafter, based on FIG.2 and FIG.3, the 1st form example of the gas supply method of using the liquefied gas supply apparatus shown to this embodiment and supplying gas continuously to a gas use place is demonstrated.

  When both the gas supply systems A and B are in the standby state (step 51), the control means 16 selects one of the gas supply system A and B, for example, the gas supply system The A-system automatic opening / closing valve 14a is opened to start gas supply from the gas supply system A system (step 52). At this time, the automatic opening / closing valve 14b of the gas supply system B system continues to be closed, and the gas supply to the gas user is performed by the gas supply system A system alone. Further, the pressure indicating controller 13a is instructed by the control means 16 to a reference set pressure preset in the control means 16, for example, 0.5 MPa, and the secondary pressure of the pressure indicating controller 13a is the reference setting pressure. The valve opening degree of the valve portion 18a is automatically adjusted so as to be 0.5 MPa.

  Further, the control means 16 sets the amount of the liquefied gas in the liquefied gas container 11a from the detection value of the weighing scale 12a to 100% of the weight of the new liquefied gas container 11a filled with the preset amount of liquefied gas. The weight of the liquefied gas container 11a during gas supply is monitored as a residual gas rate [%] (step 53), and for example, the residual gas rate is reduced until the residual gas rate falls below a preset first residual gas amount setting value. Until the gas rate becomes 30% or less, the gas supply in the gas supply system A alone is continued by repeating the step 52 and the step 53.

  If it is determined in step 53 that the residual gas ratio in the liquefied gas container 11a has become 30% or less, the process proceeds to step 54, where the set pressure of the gas supply system A is changed, and the pressure indicating controller 13a is controlled from the control means 16. A pressure higher than the reference set pressure (0.5 MPa), for example, a preset 0.53 MPa is instructed as the second set pressure, and the pressure on the secondary side of the pressure regulating valve 13a detected by the pressure detection unit 19a is The valve opening degree of the valve portion 18a is automatically adjusted so that the newly set second set pressure is 0.53 MPa. At the same time, an opening signal is sent from the control means 16 to the automatic opening / closing valve 14b of the gas supply system B, the automatic opening / closing valve 14b is opened, and the supply of the evaporated gas in the liquefied gas container 11b of the gas supply system B system begins. The supply system A system and the gas supply system B system are in a state of supplying gas in parallel.

  At this time, since the reference set pressure of 0.5 MPa is instructed to the pressure indicating controller 13b of the gas supply system B, the gas having a high set pressure (0.53 MPa) immediately after the start of the parallel supply of gases. The amount of gas supply from the supply system A is increasing. As the gas supply progresses, the residual gas rate of the liquefied gas container 11a gradually decreases from 30%, and when the evaporation amount of the liquefied gas decreases as the residual gas rate decreases, the secondary side of the pressure indicating controller 13a After the valve portion 18a of the pressure indicating controller 13a is fully opened, the evaporation amount of the liquefied gas in the liquefied gas container 11a is reduced. As a result, the pressure on the secondary side of the pressure regulating valve 13a gradually decreases, and it becomes impossible to supply a gas at a predetermined flow rate to the gas user only from the gas supply system A system. As described above, when the gas supply amount from the gas supply system A system is lowered, the gas supply system B system supplies the gas at a predetermined flow rate to the gas user by performing the gas supply in parallel.

  The control means 16 also monitors the residual gas rate [%] in the liquefied gas container 11a even when the gas supply systems A and B are supplied in parallel (step 55), and the residual gas in the liquefied gas container 11a. Until the rate becomes lower than the preset second residual gas amount setting value, for example, until the residual gas rate becomes equal to or less than 3% set in advance, the steps 54 and 55 are repeated in parallel. Continue supplying.

  If it is determined in step 55 that the residual gas ratio in the liquefied gas container 11a has become 3% or less, the process proceeds to step 56, where the automatic open / close valve 14a of the gas supply system A system is closed and the gas from the gas supply system A system is closed. The supply is stopped, and the process proceeds to step 57 where the gas supply system B system supplies the gas to the gas user alone. In the gas supply system A system, the liquefied gas container 11a is replaced in step 58, and the remaining gas is supplied. The liquefied gas container 11a having a gas rate of 3% or less is removed, and a new liquefied gas container 11a (residual gas rate 100%) is connected to the gas supply system A. If it is determined in step 59 that the replacement standard for the new liquefied gas container 11a is acceptable, the process proceeds to step 60, where the gas supply system A enters a standby state. At the same time, the pressure instructed to the pressure indicating controller 13a is returned to the reference set pressure of 0.5 MPa.

  When the gas supply system B alone is supplying gas, the pressure indicating controller 13b is instructed by the control means 16 to set the reference set pressure of 0.5 MPa. The residual gas rate of the liquefied gas container 11b is monitored based on the detected value of the weighing scale 12b. If it is determined in step 61 that the residual gas ratio of the liquefied gas container 11b is 30% or less, the process proceeds to step 62, where the command pressure of the pressure command controller 13b of the gas supply system B system is set to the second set pressure of 0.53 MPa. At the same time, the automatic opening / closing valve 14a of the gas supply system A system opens, and the gas supply system A system and the gas supply system B system supply gas in parallel.

  If it is determined in step 63 that the residual gas ratio of the liquefied gas container 11b has become 3% or less, the automatic on-off valve 14b of the gas supply system B system is closed in step 64, and the process proceeds to step 65 to proceed to the gas supply system A system. In the gas supply system B system, the liquefied gas container 11b is replaced at step 66, and the replacement standard of the liquefied gas container 11b is determined to be acceptable at step 67. Then, it progresses to step 68 and the gas supply system B system will be in a standby state.

  When the single gas supply from the gas supply system A system in step 65 starts, the process returns to step 52, and the gas supply system B system in the standby state in step 68 has the gas supply system A system from the step 53. When the routine proceeds to step 54, the standby state is switched to the gas supply state. Hereinafter, by repeating these steps, gas supply is continuously performed from both the gas supply systems A and B to the gas user.

  FIG. 3 shows a change in the residual gas rate of the liquefied gas containers 11a and 11b with the passage of time when the gas is supplied in this way, for example, the number of days (FIG. 3A), the gas supply system A system, Changes in the supply pressure of the gas, which is the secondary side pressure of the B system pressure indicating controllers 13a and 13b (FIG. 3B), and changes in the flow rates of the supply gas in the gas supply system A system and B system (FIG. 3 ( c)), each showing a change in the valve opening degree of the valve portions 18a, 18b in the pressure indicating controllers 13a, 13b (FIG. 3 (d)), showing the change in each state from step 52 in FIG. Yes.

  Since the gas supply system A alone supplies gas for a while from the start, the residual gas rate in the liquefied gas container 11a gradually decreases due to evaporation of the liquefied gas (FIG. 3 (a)). The supply pressure of the system A system maintains the reference set pressure of 0.5 MPa, the supply pressure of the standby gas supply system B system is 0 (zero) (FIG. 3B), and the supply pressure of the gas supply system A system The gas flow rate is 300 L / min (0 ° C., 1 atmospheric pressure converted value) required by the gas user, and the gas flow rate of the gas supply system B system is 0 (zero) (FIG. 3C). Further, the opening degree of the valve portion 18a in the pressure indicating controller 13a of the gas supply system A system gradually increases as the evaporation amount decreases due to the decrease in the residual gas rate of the liquefied gas container 11a, and the gas supply system B system The opening degree of the valve portion 18b in the pressure regulating valve 13b is 0 (zero) (FIG. 3 (d)).

  When time passes and the residual gas ratio of the liquefied gas container 11a becomes 30% or less (elapsed time 7), the set pressure of the gas supply system A system is changed from 0.5 MPa to 0.53 MPa, and the pressure indicating controller 13a As the opening of the valve portion 18a increases in the gas supply system A, the supply pressure of the gas supply system A increases, and the automatic open / close valve 14b opens to start supplying the gas evaporated in the liquefied gas container 11b of the gas supply system B. Then, a parallel supply state is established (step 54).

  In this parallel supply state, the residual gas ratios of the liquefied gas containers 11a and 11b are both reduced by evaporation of the liquefied gas. The supply pressure of the gas supply system A system temporarily rises to 0.53 MPa when the valve portion 18a in the pressure indicating controller 13a is opened. However, the supply pressure of the gas supply system A is reduced due to a decrease in the residual gas rate of the liquefied gas container 11a. Accordingly, even if the opening of the valve portion 18a in the pressure indicating controller 13a is fully opened (opening 100%), the supply pressure gradually decreases. On the other hand, the supply pressure of the gas supply system B is maintained at the reference set pressure of 0.5 MPa by the pressure indicating controller 13b. When the gas flow rate of the gas supply system A system and the gas flow rate of the gas supply system B system are gradually reduced with the decrease in the evaporation amount of the liquefied gas in the gas supply system A system, The gas flow rate of the gas supply system B system gradually increases so as to be 300 L / min.

  When the remaining gas ratio in the liquefied gas container 11a becomes 3% or less due to the passage of time in the parallel supply state (elapsed time 12), the automatic on-off valve 14a of the gas supply system A system is closed and the gas from the gas supply system A system is closed. The supply is stopped (step 56), and the supply from the gas supply system B is performed independently (step 57). The liquefied gas container 11a of the gas supply system A system is replaced and the remaining gas in the liquefied gas container 11a until the residual gas ratio of the liquefied gas container 11b becomes 30% or less from the single supply from the gas supply system B system. The rate becomes 100% and a standby state is entered (elapsed time 14, step 60).

  Thereafter, when the residual gas ratio of the liquefied gas container 11b becomes 30% or less, the gas supply system A system and the gas supply system B system are in parallel supply (elapsed time 18, step 62), and the remaining liquefied gas container 11b remains. When the gas rate becomes 3% or less, the gas supply system A is independently supplied (elapsed time 23, step 65). While the gas supply is continuously performed in the procedure shown in FIG. 2, the residual gas ratio of the liquefied gas containers 11a and 11b, the supply pressure of the gas supply system A system and the B system, the gas supply system A system and the B system As shown in FIG. 3, the opening degree of the valve portions 18a and 18b in the flow rate and pressure indicating controllers 13a and 13b repeats the same change alternately in the gas supply system A system and the B system over time. As a result, the gas is continuously supplied to the gas user at a pressure of 0.5 MPa and a flow rate of 300 L / min, and the liquefied gas in the liquefied gas containers 11a and 11b is used until the residual gas ratio becomes 3%. Is done.

  Next, based on FIG.4 and FIG.5, the 2nd example of a gas supply method is demonstrated. The basic procedure set in the control means 16 is set to the same procedure as that shown in FIG. 2 in the first embodiment.

  When both the gas supply systems A and B are in the standby state (step 71), the control means 16 selects one of the gas supply system A and B, for example, the gas supply system The A-system automatic opening / closing valve 14a is opened to start gas supply from the gas supply system A system (step 72). At this time, the automatic opening / closing valve 14b of the gas supply system B system continues to be closed, and the gas supply to the gas user is performed by the gas supply system A system alone. Further, the pressure indicating controller 13a is instructed by the control means 16 to a reference set pressure preset in the control means 16, for example, 0.5 MPa, and the secondary pressure of the pressure indicating controller 13a is the reference setting pressure. The valve opening degree of the valve portion 18a is automatically adjusted so as to be 0.5 MPa.

  Further, the control means 16 sets the amount of the liquefied gas in the liquefied gas container 11a from the detection value of the weighing scale 12a to 100% of the weight of the new liquefied gas container 11a filled with the preset amount of liquefied gas. The weight of the liquefied gas container 11a during the gas supply is monitored as a residual gas rate [%] (step 73), and for example, the residual gas rate is reduced until the residual gas rate falls below a preset first residual gas amount set value. Until the gas rate becomes 30% or less, step 72 and step 73 are repeated to continue the gas supply in the gas supply system A alone.

  If it is determined in step 73 that the residual gas ratio of the liquefied gas container 11a has become 30% or less, the process proceeds to step 74, and an instruction to fully open the valve portion 18a is output from the control means 16 to the pressure indicating controller 13a. The valve portion 18a is fully opened. At the same time, an opening signal is sent from the control means 16 to the automatic opening / closing valve 14b of the gas supply system B, the automatic opening / closing valve 14b is opened, and the supply of the evaporated gas in the liquefied gas container 11b of the gas supply system B system begins. The supply system A system and the gas supply system B system are in a state of supplying gas in parallel.

  At this time, since the reference set pressure of 0.5 MPa is instructed to the pressure indicating controller 13b of the gas supply system B system, the gas supply system in which the valve portion 18a is fully opened immediately after the start of parallel supply of gases. The amount of gas supplied from the A system is increasing. When the residual gas rate of the liquefied gas container 11a gradually decreases from 30% as the gas supply progresses, the pressure on the secondary side of the pressure indicating controller 13a gradually decreases even when the valve portion 18a is fully opened, and the gas supply system From only the A system, it becomes impossible to supply a gas at a predetermined flow rate to the gas user. As described above, when the gas supply amount from the gas supply system A system is lowered, the gas supply system B system supplies the gas at a predetermined flow rate to the gas user by performing the gas supply in parallel.

  The control means 16 also monitors the residual gas rate [%] in the liquefied gas container 11a even when the gas supply systems A and B are supplied in parallel (step 75), and the residual gas in the liquefied gas container 11a. Until the rate becomes lower than the preset second residual gas amount set value, for example, until the residual gas rate becomes equal to or less than 3% set in advance, Step 74 and Step 75 are repeated in parallel. Continue supplying.

  If it is determined in step 75 that the residual gas ratio in the liquefied gas container 11a has become 3% or less, the routine proceeds to step 76, where the automatic open / close valve 14a of the gas supply system A system is closed and the gas from the gas supply system A system is closed. The supply is stopped, the process proceeds to step 77, and the gas supply system B system supplies gas to the gas user alone. In the gas supply system A system, the liquefied gas container 11a is replaced at step 78, and the remaining gas is supplied. The liquefied gas container 11a having a gas rate of 3% or less is removed, and a new liquefied gas container 11a (residual gas rate 100%) is connected to the gas supply system A. If it is determined in step 79 that the replacement standard for the new liquefied gas container 11a is acceptable, the process proceeds to step 80, where the gas supply system A enters a standby state. At the same time, a reference set pressure of 0.5 MPa is instructed to the pressure indicating controller 13a.

  When the gas supply system B alone is supplying gas, the pressure indicating controller 13b is instructed by the control means 16 to set the reference set pressure of 0.5 MPa. The residual gas rate of the liquefied gas container 11b is monitored based on the detected value of the weighing scale 12b. If it is determined in step 81 that the residual gas ratio of the liquefied gas container 11b is 30% or less, the process proceeds to step 82, and the valve unit 18b is fully opened from the control means 16 to the pressure indicating controller 13b of the gas supply system B system. An instruction is output, the valve section 18b is fully opened, and the automatic opening / closing valve 14a of the gas supply system A system is opened so that the gas supply system A system and the gas supply system B system supply gas in parallel.

  If it is determined in step 83 that the residual gas ratio in the liquefied gas container 11b has become 3% or less, the automatic open / close valve 14b of the gas supply system B system is closed in step 84, and the process proceeds to step 85 to proceed to the gas supply system A system. In the gas supply system B system, the liquefied gas container 11b is replaced at step 86, and the replacement standard of the liquefied gas container 11b is determined to be acceptable at step 87. Then, it progresses to step 88 and the gas supply system B system will be in a standby state.

  When the gas supply from the gas supply system A system in step 85 starts alone, the process returns to step 72, and the gas supply system B system in the standby state in step 88 is changed from the step 73 in the gas supply system A system. When the routine proceeds to step 74, the standby state is switched to the gas supply state. Hereinafter, by repeating these steps, gas supply is continuously performed from both the gas supply systems A and B to the gas user.

  FIG. 5 shows changes in the residual gas ratio of the liquefied gas containers 11a and 11b with the passage of time when the gas is supplied in this way, for example, the number of days (FIG. 5A), the gas supply system A system, Changes in the supply pressure of the gas, which is the secondary pressure of the B system pressure indicating controllers 13a and 13b (FIG. 5B), and changes in the flow rates of the gas supply systems A and B (see FIG. c)), each showing a change in the valve opening degree of the valve portions 18a, 18b in the pressure indicating controllers 13a, 13b (FIG. 5 (d)), showing the change in each state from step 72 in FIG. Yes.

  Since the gas supply system A alone supplies gas for a while from the start, the residual gas rate in the liquefied gas container 11a gradually decreases due to evaporation of the liquefied gas (FIG. 5 (a)). The supply pressure of the system A system is maintained at the reference set pressure of 0.5 MPa, the supply pressure of the standby gas supply system B system is 0 (zero) (FIG. 5B), and the supply pressure of the gas supply system A system The gas flow rate is 300 L / min (0 ° C., 1 atmospheric pressure converted value) required by the gas user, and the gas flow rate of the gas supply system B system is 0 (zero) (FIG. 5C). Further, the opening degree of the valve portion 18a in the pressure indicating controller 13a of the gas supply system A system gradually increases as the evaporation amount decreases due to the decrease in the residual gas rate of the liquefied gas container 11a, and the gas supply system B system The opening degree of the valve portion 18b in the pressure regulating valve 13b is 0 (zero) (FIG. 5 (d)).

  When time passes and the residual gas ratio of the liquefied gas container 11a becomes 30% or less (elapsed time 7), the valve portion 18a in the pressure indicating controller 13a of the gas supply system A system has an opening degree of 100% (fully opened state). At the same time, when the automatic opening / closing valve 14b is opened, supply of the gas evaporated in the liquefied gas container 11b of the gas supply system B system starts, and a parallel supply state is established (step 74). At this time, the supply pressure of the gas supply system A system temporarily rises to the reference set pressure of 0.5 MPa or more when the valve portion 18a is fully opened.

  In this parallel supply state, the residual gas ratios of the liquefied gas containers 11a and 11b are both reduced by evaporation of the liquefied gas. The supply pressure of the gas supply system A system is 0.5 MPa or more immediately after the start of parallel supply because the valve portion 18a is fully open, but the evaporation amount due to a decrease in the residual gas rate of the liquefied gas container 11a As the pressure decreases, the supply pressure gradually decreases. On the other hand, the supply pressure of the gas supply system B is maintained at the reference set pressure of 0.5 MPa by the pressure indicating controller 13b. When the gas flow rate of the gas supply system A system and the gas flow rate of the gas supply system B system are gradually reduced with the decrease in the evaporation amount of the liquefied gas in the gas supply system A system, The gas flow rate of the gas supply system B system gradually increases so as to be 300 L / min.

  When the remaining gas ratio in the liquefied gas container 11a becomes 3% or less due to the passage of time in the parallel supply state (elapsed time 12), the automatic on-off valve 14a of the gas supply system A system is closed and the gas from the gas supply system A system is closed. The supply is stopped (step 76), and the supply is performed independently from the gas supply system B (step 77). The liquefied gas container 11a of the gas supply system A system is replaced and the remaining gas in the liquefied gas container 11a until the residual gas ratio of the liquefied gas container 11b becomes 30% or less from the single supply from the gas supply system B system. The rate becomes 100% and a standby state is entered (elapsed time 14, step 80).

  Thereafter, when the residual gas ratio of the liquefied gas container 11b becomes 30% or less, the gas supply system A system and the gas supply system B system are in parallel supply (elapsed time 18, step 82), and the remaining liquefied gas container 11b remains. When the gas rate becomes 3% or less, the gas supply system A is independently supplied (elapsed time 23, step 85). While the gas supply is continuously performed in the procedure shown in FIG. 4, the residual gas ratio of the liquefied gas containers 11a and 11b, the supply pressure of the gas supply system A system and the B system, the gas supply system A system and the B system As shown in FIG. 5, the opening degree of the valve portions 18a and 18b in the flow rate and pressure indicating controllers 13a and 13b alternately repeats the same change in the gas supply system A and system B over time. The gas whose flow rate is controlled to 300 L / min is continuously supplied to the gas use destination, and the liquefied gas in the liquefied gas containers 11a and 11b is used until the residual gas ratio becomes 3%.

  In the gas supply method shown in the second embodiment, immediately after the start of parallel supply, one of the valve portions 18a and 18b in the pressure indicating controllers 13a and 13b is fully opened, so that the use gas supply path 15 Although the pressure temporarily rises, as in the liquefied gas supply apparatus shown in FIG. 1, a pressure regulator 17 is provided in the use gas supply path 15 where the gas supply systems A and B join, and the gas use destination By adjusting the pressure of the gas supplied to the gas to a pressure desired by the user of the gas, which is lower than the reference set pressure of 0.5 MPa, it is possible to prevent pressure fluctuation and flow rate fluctuation of the supply gas. Also in the first embodiment of the gas supply method, the use gas supply path 15n pressure regulator 17 can be provided, and when such a pressure regulator is incorporated in the gas use equipment, The pressure regulator 17 in the use gas supply path 15 can be omitted.

  In the flowchart shown in FIG. 2 showing the first embodiment of the method of the present invention and in FIG. 4 showing the second embodiment of the method of the present invention, the gas supply is automatically performed when the residual gas ratio becomes 3% or less. Switching from parallel to stand-alone and replacing the liquefied gas container, but when the residual gas rate is 30% or less and parallel supply is being performed, for example, an alarm is output to artificially gas The supply can be switched from parallel to single and the liquefied gas container can be replaced.

  Moreover, although the gas supply system has been described with an example of two systems, it can be the same even when there are three or more gas supply systems. For example, when the first system is supplying gas, By setting the first standby state and the third system to the second standby state, and switching to the gas supply from the second system, the third system is set to the first standby state and the first system is set to the second standby state. The time for replacing the liquefied gas container can be extended, and the redundancy of the liquefied gas supply device can be improved. Furthermore, when there are three or more gas supply systems, the first system with a low residual gas rate is in the first gas supply state, the second system with a high residual gas rate is in the second gas supply state, and the system below the third system is in the standby state When the first system is in a standby state after replacing the container, the second system with a low residual gas rate is set as the first gas supply state, and the third system with a high residual gas rate is set as the second gas supply state. It is possible to cope with a large amount of gas supply by setting so as to.

  The type of the liquefied gas is not particularly limited, and the liquefied gas amount detecting means for detecting the liquefied gas amount in the liquefied gas container is not limited to the weight meter, but the liquefied gas amount in the liquefied gas container. Any device can be used as long as it can detect the water level. For example, various liquid level gauges can be used. It is also possible to indirectly detect the amount of liquefied gas in the liquefied gas container using a pressure gauge. Furthermore, the second set pressure relative to the reference set pressure may be set according to conditions such as the type of gas, supply pressure, supply amount, etc., and may be set to a pressure that allows parallel supply. Further, the numerical value of the residual gas rate for switching the supply state can also be appropriately set according to conditions such as the type of gas, supply pressure, and supply amount. Furthermore, means for heating the liquefied gas container to promote the evaporation of the liquefied gas can be added to the liquefied gas container within the range permitted by laws and regulations (General High Pressure Gas Safety Regulations Article 60). .

  DESCRIPTION OF SYMBOLS 11a, 11b ... Liquefied gas container, 12a, 12b ... Weight meter, 13a, 13b ... Pressure indication controller, 14a, 14b ... Automatic on-off valve, 15 ... Used gas supply path, 16 ... Control means, 17 ... Pressure regulator , 18a, 18b ... valve part, 19a, 19b ... pressure detection part

Claims (2)

In a liquefied gas supply method using a liquefied gas supply device that evaporates liquefied gas filled in a plurality of liquefied gas containers and supplies the gas to a user, a liquefied gas container connected to each of a plurality of gas supply systems; Liquefied gas amount detecting means for detecting the amount of liquefied gas in each liquefied gas container, pressure adjusting means for adjusting the pressure on the secondary side provided in each gas supply system, and provided in each gas supply system, respectively Gas supply shut-off means and a use gas supply path for joining the gas supplied from a plurality of gas supply systems to supply to the gas use destination, and each gas supply system includes the liquefied gas amount detection means. The secondary pressure of the pressure adjusting means is controlled to any one of a plurality of preset pressures based on the amount of liquefied gas in the liquefied gas container detected in step 1, and the gas supply system The gas-used using liquefied gas supply device comprising a control means for controlling opening and closing respectively the gas supply interrupting means provided on said gas supply cutoff means and the other gas supply system is provided in A liquefied gas supply method for continuously supplying a gas, wherein the control means opens a first gas supply shut-off means provided in a first gas supply system and opens a secondary of the first pressure adjusting means. When the side set pressure is set to the reference set pressure and gas is supplied from the first liquefied gas container, the amount of liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detecting means is When lower than the preset first residual gas amount set value, a pressure higher than the reference set pressure is set as the secondary set pressure of the first pressure adjusting means, and provided in the second gas supply system The second being There line gas supply from both in parallel with the first gas supply system and a second gas supply system by opening the scan supply cut-off means, said first liquefied gas detected by the first liquefied gas amount detecting means When the amount of liquefied gas in the container falls below a second residual gas amount set value set to a lower liquefied gas amount than the first residual gas amount set value, the first gas supply shut-off means is closed to The liquefied gas supply method of stopping the gas supply from the gas supply system and switching to the gas supply from the second gas supply system . In a liquefied gas supply method using a liquefied gas supply device that evaporates liquefied gas filled in a plurality of liquefied gas containers and supplies the gas to a user, a liquefied gas container connected to each of a plurality of gas supply systems; Liquefied gas amount detecting means for detecting the amount of liquefied gas in each liquefied gas container, pressure adjusting means for adjusting the pressure on the secondary side provided in each gas supply system, and provided in each gas supply system, respectively Gas supply shut-off means and a use gas supply path for joining the gas supplied from a plurality of gas supply systems to supply to the gas use destination, and each gas supply system includes the liquefied gas amount detection means. The secondary pressure of the pressure adjusting means is controlled to any one of a plurality of preset pressures based on the amount of liquefied gas in the liquefied gas container detected in step 1, and the gas supply system Control means for controlling the opening and closing of the gas supply shut-off means provided in the gas supply system and the gas supply shut-off means provided in another gas supply system, respectively. A liquefied gas supply method that continuously supplies gas to the gas user using a liquefied gas supply device that is a pressure adjusting valve that adjusts the pressure on the secondary side by adjusting the opening of The control means opens the first gas supply cutoff means provided in the first gas supply system, sets the secondary set pressure of the first pressure regulating valve to the reference set pressure, and sets the first liquefied gas When supplying gas from the container, when the amount of liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detection means falls below a preset first residual gas amount set value The first pressure regulating valve is fully open As well as to, have a row of gas supply in parallel from both the first gas supply system by opening the second gas supply interrupting means provided in the second gas supply system and a second gas supply system, A second residual gas amount setting value in which the liquefied gas amount in the first liquefied gas container detected by the first liquefied gas amount detection means is set to a liquefied gas amount smaller than the first residual gas amount setting value. The liquefied gas supply method of switching to gas supply from the second gas supply system by closing the first gas supply shut-off means and stopping the gas supply from the first gas supply system when the value is less than .

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