TWI530639B - Liquefied gas supply device and method - Google Patents

Description

Liquefied gas supply device and method

The present invention relates to a liquefied gas supply device and method, and more particularly to a liquefied gas supply device and method for evaporating a liquefied gas filled in a plurality of liquefied gas containers and supplying the gas to a gas use end.

A liquefied gas supply method for evaporating a liquefied gas filled in a plurality of liquefied gas containers and supplying the gas to a gas use end is known to increase the pressure in a plurality of liquefied gas containers (bulk containers). The pressure means monitors the pressure in each of the liquefied gas containers, and supplies gas from the first liquefied gas container having a relatively high pressure. When the pressure in the first liquefied gas container decreases, the supply of the gas is switched from the second. The liquefied gas container is operated, and the first liquefied gas container whose pressure has been lowered is exchanged, whereby the gas supply to the gas use end is continuously performed. (For example, refer to Patent Document 1)

[Patent Literature]

(Patent Document 1) Japanese Patent Laid-Open Publication No. 2007-231982

However, as in the case of the 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, but a gas having a low vapor pressure near normal temperature (for example, liquefied ammonia) can be used. In the case where the residual amount of the liquefied gas in the liquefied gas container is 30% or less of the volume of the container, the amount of evaporation immediately decreases, and it is difficult to supply the gas at the flow rate required for the gas use end. Therefore, when the flow rate of the liquefied gas in the liquefied gas container is about 30% of the volume of the container, the amount of liquefied gas remaining in the liquefied gas container must be switched, and the liquefied gas remaining in the gas supply must be switched. In the case of a small liquefied gas container, helium can continuously supply a gas of a predetermined flow rate to the gas use end.

Therefore, there is a problem that the liquefied ammonia filled in the liquefied gas container cannot be sufficiently used, and the utilization efficiency of the liquefied ammonia is lowered, and the exchange cycle of the liquefied gas container is shortened. Further, the liquefied gas container filled with the liquefied ammonia can be heated to a high temperature to promote the evaporation of the liquefied ammonia, thereby supplying the evaporated ammonia at a predetermined flow rate and evaporating the liquefied ammonia in most of the liquefied gas containers. In order to heat large large containers to special heating equipment at high temperatures, there is a problem that equipment costs and running costs are greatly increased.

Accordingly, it is an object of the present invention to provide a liquefied gas supply device and method which can improve the liquefied gas filled in a liquefied gas container in a simple device configuration and sequence (especially a liquefied gas having a low vapor pressure near normal temperature such as liquefied ammonia). Utilization efficiency.

In order to achieve the above object, the liquefied gas supply device of the present invention is configured to evaporate a liquefied gas filled in a plurality of liquefied gas containers to supply a gas use end, and is characterized in that the liquefied gas container is provided in a plurality of liquefied gas containers. The gas supply system and the liquefied gas amount detecting means respectively detect the amount of the liquefied gas in each of the liquefied gas containers; the pressure adjusting means is provided in each of the gas supply systems to adjust the pressure on the secondary side; and the gas supply blocking means is Provided in each of the gas supply systems; and the end gas supply path, the gas supplied from the plurality of gas supply systems is confluent and supplied to the gas use end; each gas supply system is provided with a control means based on the liquefied gas The amount of liquefied gas in the liquefied gas container detected by the amount detecting means controls the pressure on the secondary side of the pressure adjusting means to one of a plurality of preset pressures set in advance, and is separately provided to the gas supply system. The gas supply blocking means and the other gas supply The gas supply system of the blocking means to open and close control.

Further, the liquefied gas supply device of the present invention is characterized in that the pressure adjusting means is a pressure regulating valve that adjusts a flow path area through which a gas flows by a valve opening degree, thereby adjusting a pressure on the secondary side. .

In the first configuration of the liquefied gas supply method of the present invention, the gas supply device continuously supplies gas to the gas use end, and the control means is opened in the first gas supply system. (1) When the gas supply is supplied from the first liquefied gas container and the gas is supplied from the first liquefied gas container, the first liquefied gas amount detecting means detects the first gas pressure blocking means. When the amount of the liquefied gas in the liquefied gas container is lower than the preset first residual gas amount setting value, the secondary side setting pressure of the first pressure adjusting means is set to a pressure higher than the reference setting pressure, and the setting is turned on. In the second gas supply blocking means of the second gas supply system, gas supply is performed in parallel from both the first gas supply system and the second gas supply system.

Further, in the second configuration of the liquefied gas supply method of the present invention, the liquefied gas supply device using the pressure adjustment valve as the pressure adjustment means, and the gas supply end is continuously supplied to the gas supply end, wherein the control means is When the first gas supply blocking means provided in the first gas supply system is opened, and the secondary side setting pressure of the first pressure adjusting means is set to the reference set pressure, and the gas is supplied from the first liquefied gas container, When the amount of the liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detecting means is lower than a predetermined first residual gas amount setting value, the secondary side pressure of the first pressure adjusting means is set to be higher than the above The reference pressure is set to a higher pressure, and the second gas supply blocking means provided in the second gas supply system is opened, and gas supply is performed in parallel from both the first gas supply system and the second gas supply system.

Further, the liquefied gas supply method of the present invention is characterized in that the amount of the liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detecting means is set lower than the first residual gas amount. When the second residual gas amount setting value of the liquefied gas amount is small, the first gas supply blocking means is turned off, the gas supply from the first gas supply system is stopped, and the gas supply from the second gas supply system is switched.

According to the present invention, a plurality of gas supply systems can be switched in accordance with the amount of liquefied gas connected to the liquefied gas container of each gas supply system, whereby the gas supply end is continuously supplied with gas, and the liquefied gas amount detecting means is utilized. The control means for actuating the amount of the liquefied gas to be controlled, the set pressure of the secondary side of the pressure adjusting means is controlled, or the pressure regulating valve is fully opened, whereby the liquefied gas container having a small amount of liquefied gas can be liquefied. The gas is supplied to the gas use end. Thereby, the utilization efficiency of the liquefied gas can be improved, and the exchange cycle of the liquefied gas container can be prolonged.

First, as shown in Fig. 1, the liquefied gas supply device shown in the present embodiment is a gas supply system A system and a B system having a plurality of systems (two in the present embodiment). The liquefied gas containers 11a and 11b are connected to each of the gas supply system A system and the B system, and the weight gauges 12a and 12b are used as means for detecting the amount of liquefied gas in each of the liquefied gas containers 11a and 11b. The pressure indicating regulators (PIC) 13a, 13b are pressure adjusting means respectively provided in each of the gas supply system A system and the B system, and adjusting the pressure on the secondary side to the indicated pressure; the automatic opening and closing valves 14a, 14b Each of the gas supply system A system and the B system is provided as a gas supply blocking means for supplying and stopping the gas, and the end gas supply path 15 is used to supply the gas supply system A and the system B. The supplied gas is merged and supplied to the gas use end; and the control means 16 is the residual amount of the liquefied gas in the liquefied gas containers 11a, 11b detected by the weight gauges 12a, 12b Controls the pressure indicator controller 13a, 13b and the automatic on-off valve 14a, 14b. Further, the use end gas supply path 15 shown in the present embodiment includes a pressure regulator 17 for adjusting the pressure of the gas supplied to the gas use end to a predetermined pressure.

The pressure indicating regulators 13a and 13b include valve portions 18a and 18b for adjusting the flow path area of the gas flow by the opening degree of the valve, and pressure detecting portions 19a and 19b for detecting the secondary side pressure, and the pressure indicating unit is used to indicate the regulator. The pressure adjustment performed by the control means 16 is performed based on the pressure indicated by the control means 16 and the pressure detected by the pressure detecting portions 19a, 19b, and the valve opening degree of the valve portions 18a, 18b is controlled to be the pressure detecting portion. The pressure detected by 19a, 19b is consistent with the pressure indicated by control means 16.

When gas supply is performed from each of the liquefied gas containers 11a and 11b of the gas supply system A system and the B system, the pressure indicating regulators 13a and 13b are instructed to set the pressure to a predetermined state, and the automatic opening and closing valves 14a and 14b are turned on. When the gas supply is stopped, the automatic opening and closing valves 14a and 14b are in a closed state. The exchange of the liquefied gas containers 11a and 11b is performed when the automatic opening and closing valves 14a and 14b are in a closed state, and after the liquefied gas container is exchanged, until the control means 16 opens the automatic opening and closing valves 14a and 14b, the gas supply is not performed. Becomes standby.

In the following, a first embodiment of a gas supply method for continuously supplying a gas to a gas use end using the liquefied gas supply device shown in the present embodiment will be described with reference to FIG. 2 and FIG.

When the two gas supply systems A and B systems are in a standby state (step 51), the control means 16 selects either the gas supply system A system or the B system, for example, the automatic opening and closing valve of the gas supply system A system is opened. 14a, gas supply from the gas supply system A system is started (step 52). At this time, the automatic opening and closing valve 14b of the gas supply system B system is continuously closed, and the gas supply to the gas use end is performed separately by the gas supply system A system. Further, the pressure indicating adjuster 13a is configured such that the control means 16 instructs the reference setting pressure (for example, 0.5 MPa) set in advance by the control means 16, and the pressure on the secondary side of the pressure indicating adjuster 13a becomes the reference set pressure of 0.5 MPa. The valve opening degree of the valve portion 18a is automatically adjusted.

Further, the control means 16 monitors the amount of the liquefied gas in the liquefied gas container 11a by the weight of the new liquefied gas container 11a filled in the predetermined amount of the liquefied gas, and the amount of the liquefied gas in the liquefied gas container 11a. The liquefied gas container 11a is used as the residual gas rate [%] (step 53) until the residual gas rate is lower than a predetermined value of the first residual gas amount set value (for example, to the residual gas rate) When it is 30% or less, the above-described step 52 and step 53 are repeated, and the gas supply is continuously performed by the gas supply system A system.

When it is determined in step 53 that the residual gas rate of the liquefied gas container 11a is 30% or less, the routine proceeds to step 54 where the set pressure of the gas supply system A system is changed, and the control means 16 instructs the pressure indicating regulator 13a to be higher than the above reference. The pressure higher than the set pressure (0.5 MPa), for example, 0.53 MPa which is set in advance, automatically adjusts the valve opening degree of the valve portion 18a as the second set pressure, and causes the pressure regulating valve 13a detected by the pressure detecting portion 19a to be twice. The side pressure becomes the newly set second set pressure of 0.53 MPa. Simultaneously, the control unit 16 sends an opening signal to the automatic opening and closing valve 14b of the gas supply system B system, opens the automatic opening and closing valve 14b, and starts the supply of the gas evaporated by the liquefied gas container 11b of the gas supply system B system to become a gas. The supply system A system and the gas supply system B system perform the state of gas supply in parallel.

At this time, since the pressure indicating regulator 13b of the gas supply system B system is instructed to set the reference set pressure to 0.5 MPa, the gas supply system A system having a high set pressure (0.53 MPa) is immediately after the parallel supply of the gas is started. The gas supply is large. Through the passage of the gas supply, the residual gas rate of the liquefied gas container 11a gradually decreases from 30%, and as the residual gas rate decreases, the evaporation amount of the liquefied gas also decreases, and the secondary side pressure of the pressure indicating regulator 13a is maintained at When the second set pressure is 0.53 MPa, it becomes more and more difficult. When the valve portion 18a of the pressure indicating regulator 13a is fully opened, the amount of evaporation of the liquefied gas in the liquefied gas container 11a is lowered, and the pressure regulating valve 13a is second. Since the secondary side pressure is gradually lowered, if only the gas supply system A system is used, it becomes impossible to supply a gas of a predetermined flow rate to the gas use end. As described above, when the gas supply amount from the gas supply system A system is lowered, the gas is supplied in parallel from the gas supply system B system, and the gas of a predetermined flow rate can be supplied to the gas use end.

When the two gas supply systems A and B are supplied in parallel, the control means 16 also monitors the residual gas rate [%] of the liquefied gas container 11a (step 55), and the residual gas rate to the liquefied gas container 11a becomes lower. Until the value of the second residual gas amount setting value set in advance (for example, until the residual gas rate is 3% or less set in advance), the above-described steps 54 and 55 are repeated, and the parallel supply of the gas is continued.

When it is judged in step 55 that the residual gas rate of the liquefied gas container 11a is 3% or less, the routine proceeds to step 56, the automatic opening and closing valve 14a of the gas supply system A system is closed, the gas supply from the gas supply system A system is stopped, and the process proceeds to Step 57, gas supply is performed separately from the gas supply system B system, and the liquefied gas container 11a is exchanged in the gas supply system A system in step 58 to remove the liquefied gas container having a residual gas rate of 3% or less. 11a, a new liquefied gas container 11a (residual gas rate 100%) is connected to the gas supply system A system. When it is determined in step 59 that the exchange standard of the new liquefied gas container 11a is acceptable, the process proceeds to step 60, and the gas supply system A system is in the standby state. At the same time, the pressure indicated to the pressure indicating regulator 13a is returned to the reference set pressure of 0.5 MPa.

When the gas supply is separately performed by the gas supply system B, the pressure indicating regulator 13b is instructed from the control means 16 to indicate a standard set pressure of 0.5 MPa, and in the control means 16, the liquefaction is monitored by the step 61 based on the detected value of the weight 12b. The residual gas rate of the gas container 11b. When it is determined in step 61 that the residual gas rate of the liquefied gas container 11b is 30% or less, the routine proceeds to step 62, and the instruction pressure of the pressure indicating regulator 13b of the gas supply system B system is changed to the second set pressure of 0.53 MPa, and The automatic opening and closing valve 14a of the gas supply system A system is opened, and the gas supply system A system is supplied with the gas in parallel with the gas supply system B system.

When it is determined in step 63 that the residual gas rate of the liquefied gas container 11b is 3% or less, the automatic opening and closing valve 14b of the gas supply system B system is closed in step 64, and the routine proceeds to step 65, where the gas supply system A system is separately operated. Gas supply is performed at the gas use end, and the liquefied gas container 11b is exchanged in step S in the gas supply system B. If it is determined in step 67 that the exchange standard of the liquefied gas container 11b is acceptable, the process proceeds to step 68, and the gas supply system B The system becomes standby.

If the supply of the individual gas from the gas supply system A in step 65 is started, the process returns to the above step 52, and when the gas supply system A system proceeds from the above step 53 to the step 54, the gas supply becomes the standby state in the step 68. The system B system is switched from the standby state to the gas supply state. Hereinafter, by repeating the respective steps, gas supply is continuously performed from the two gas supply systems A and B systems to the gas use end.

Fig. 3 is a graph showing changes in the residual gas rate of the liquefied gas containers 11a and 11b with time passage (e.g., the number of days passed) when the gas supply is performed (Fig. 3(a)), the gas supply system A system, and the B system. The change in the gas supply pressure of the secondary side pressure of the pressure indicating regulators 13a, 13b (Fig. 3 (b)), the flow rate of the supply gas of the gas supply system A system, the B system (Fig. 3 (c)), the pressure indication The change in the valve opening degree of the valve portions 18a and 18b in the regulators 13a and 13b (Fig. 3(d)) indicates the change of each state from the step 52 in Fig. 2 .

Since the gas supply is separately performed from the gas supply system A system in a short period from the beginning, the residual gas rate of the liquefied gas container 11a gradually decreases due to the evaporation of the liquefied gas (Fig. 3(a)), but the gas supply The supply pressure of the system A system is maintained at the reference set pressure of 0.5 MPa, and the supply pressure of the gas supply system B system in standby is 0 (zero) (Fig. 3 (b)), and the gas flow rate of the gas supply system A system is used. The required 300 L/min (0 ° C, 1 atmosphere conversion value), and the gas supply system B system gas flow rate is 0 (zero) (Fig. 3 (c)). Further, the degree of opening of the valve portion 18a in the pressure indicating regulator 13a of the gas supply system A is gradually increased as the amount of evaporation due to the decrease in the residual gas rate of the liquefied gas container 11a is decreased, and the gas supply system B is increased. The opening degree of the valve portion 18b of the pressure regulating valve 13b of the system is 0 (zero) (Fig. 3(d)).

When the time elapses and the residual gas rate 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 the opening of the valve portion 18a in the regulator 13a is opened. When the degree of supply is increased, the supply pressure of the gas supply system A system is increased, and the supply of the gas evaporated in the liquefied gas container 11b of the gas supply system B system is started by opening the automatic opening and closing valve 14b, and the supply is performed in parallel (step 54).

In the parallel supply state, the residual gas ratio of the two liquefied gas containers 11a and 11b is lowered by evaporation of the liquefied gas. The supply pressure of the gas supply system A system is temporarily increased to 0.53 MPa by opening the valve portion 18a in the pressure indicating regulator 13a, but the amount of evaporation caused by the decrease in the residual gas rate of the liquefied gas container 11a is reduced, even if The opening degree of the valve portion 18a in the pressure indicating regulator 13a is in a fully open state (opening degree 100%), and the supply pressure is still gradually lowered. On the other hand, the supply pressure of the gas supply system B system is maintained at the reference set pressure of 0.5 MPa by the pressure indicating regulator 13b. As the amount of liquefied gas vaporization of the gas supply system A system decreases, the gas flow rate of the gas supply system A system gradually decreases, and the gas flow rate of the gas supply system B system gradually increases, so that the gas flow rate and gas supply of the gas supply system A system are increased. The sum of the gas flows of the system B system became 300 L/min.

When the residual gas rate of the liquefied gas container 11a is 3% or less (elapsed time 12) due to the passage of the time in the parallel supply state, the automatic opening and closing valve 14a of the gas supply system A system is closed, and the system from the gas supply system A is stopped. The gas supply (step 56) becomes a separate supply from the gas supply system B system (step 57). When the residual gas rate from the supply of the gas supply system B to the liquefied gas container 11b is 30% or less, the liquefied gas container 11a of the gas supply system A system is exchanged, and the residual gas rate of the liquefied gas container 11a becomes 100. % becomes the standby state (elapse time 14, step 60).

After that, when the residual gas rate of the liquefied gas container 11b is 30% or less, the gas supply system A system and the gas supply system B are connected in parallel (elapse time 18, step 62), and the residual gas of the liquefied gas container 11b. When the rate is 3% or less, it becomes a separate supply of the gas supply system A system (elapse time 23, step 65). The residual gas rate of the liquefied gas containers 11a and 11b, the supply pressure of the gas supply system A system, the B system, the flow rate and pressure of the gas supply system A system, and the B system during the continuous gas supply in the order shown in Fig. 2 The opening degree indicating the opening degree of the valve portions 18a, 18b in the regulators 13a, 13b is as shown in Fig. 3. The same change is repeated by the gas supply system A system and the B system by the passage of time, thereby aligning the gas The gas in which the continuous supply pressure was controlled to 0.5 MPa and the flow rate was controlled to 300 L/min was used, and the liquefied gas in the liquefied gas containers 11a and 11b was used until the residual gas rate became 3%.

Next, a second embodiment of the gas supply method will be described with reference to Figs. 4 and 5 . The basic procedure set in the above-described control means 16 is set to the same order as the sequence shown in Fig. 2 in the first embodiment.

When the two gas supply systems A and B systems are in a standby state (step 71), one of the gas supply system A system and the B system is selected, for example, the automatic opening and closing valve 14a of the gas supply system A system is opened. The gas supply from the gas supply system A system is started (step 72). At this time, the automatic opening and closing valve 14b of the gas supply system B system is continuously closed, and the gas supply to the gas use end is separately performed by the gas supply system A system. Further, the pressure indicating adjuster 13a is instructed by the control means 16 to set the reference setting pressure (for example, 0.5 MPa) set in advance by the control means 16, and the valve opening degree of the valve portion 18a is automatically adjusted to cause the pressure indicating the regulator 13a twice. The side pressure becomes the reference set pressure of 0.5 MPa.

Further, the control means 16 monitors the amount of the liquefied gas in the liquefied gas container 11a from the detected value of the weight 12a by the weight of the new liquefied gas container 11a filled with the predetermined amount of the liquefied gas, and supplies the gas. The liquefied gas container 11a is used as the residual gas rate [%] with respect to the weight thereof (step 73), and the above step 72 and step 73 are repeated to continue the gas supply from the gas supply system A system until the residual gas rate becomes lower. The value of the first residual gas amount set value set in advance is, for example, 30% or less of the residual gas rate.

When it is determined in step 73 that the residual gas rate of the liquefied gas container 11a is 30% or less, the process proceeds to step 74, and the pressure indicating regulator 13a is instructed by the control means 16 to output an instruction to fully open the valve portion 18a, thereby making the valve portion 18a Fully open. Simultaneously, the control unit 16 sends an opening signal to the automatic opening and closing valve 14b of the gas supply system B system, opens the automatic opening and closing valve 14b, and starts the supply of the gas evaporated by the liquefied gas container 11b of the gas supply system B system to become a gas supply. The system A system performs the state of gas supply in parallel with the gas supply system B system.

At this time, since the pressure indicating regulator 13b of the gas supply system B system is instructed to the reference set pressure of 0.5 MPa, the gas from the gas supply system A system in which the valve portion 18a is fully opened after the parallel supply of the gas is started. The supply is increasing. Since the residual gas rate of the liquefied gas container 11a gradually decreases from 30% due to the passage of the gas supply, even if the valve portion 18a is fully opened, the pressure on the secondary side of the pressure indicating regulator 13a gradually decreases, if only from the gas supply system A In the system, it is impossible to supply a gas of a predetermined flow rate to the gas use end. As described above, when the gas supply amount from the gas supply system A system is lowered, gas supply is performed in parallel from the gas supply system B system, whereby a gas having a predetermined flow rate can be supplied to the gas use end.

When the two gas supply system A system and the B system are supplied in parallel, the control means 16 also monitors the residual gas rate [%] of the liquefied gas container 11a (step 75), and repeats the above steps 74 and 75 to continue the parallel supply of the gas. The residual gas rate of the liquefied gas container 11a is lower than a predetermined value of the second residual gas amount setting value, for example, until the residual gas rate is 3% or less of a predetermined value.

When it is judged in step 75 that the residual gas rate of the liquefied gas container 11a is 3% or less, the routine proceeds to step 76, the automatic opening and closing valve 14a of the gas supply system A system is closed, and the gas supply from the gas supply system A system is stopped. In step 77, the gas supply end is separately supplied with gas from the gas supply system B, and in the gas supply system A, the liquefied gas container 11a is exchanged in step 78, and the residual gas rate is 3% or less. The liquefied gas container 11a connects the new liquefied gas container 11a (residual gas rate 100%) to the gas supply system A system. When it is determined in step 79 that the exchange standard of the new liquefied gas container 11a has passed, the process proceeds to step 80, and the gas supply system A system is in the standby state. Simultaneously, the pressure indicating regulator 13a indicates a reference setting pressure of 0.5 MPa.

When the gas supply is performed by the gas supply system B system alone, the pressure indicating regulator 13b indicates the reference setting pressure of 0.5 MPa by the control means 16, and the control means 16 monitors the liquefied gas container 11b based on the detected value of the weight 12b by the step 81. Residual gas rate. When it is judged in step 81 that the residual gas rate of the liquefied gas container 11b is 30% or less, the routine proceeds to step 82, and the pressure indicating regulator 13b of the gas supply system B system is output from the control means 16 so that the valve portion 18b is fully opened. In response to the instruction, the valve portion 18b is fully opened, and the automatic opening and closing valve 14a of the gas supply system A system is opened, and the gas supply system A system is supplied in parallel with the gas supply system B system.

When it is determined in step 83 that the residual gas rate of the liquefied gas container 11b is 3% or less, the automatic opening and closing valve 14b of the gas supply system B system is closed in step 84, and the routine proceeds to step 85, where the gas supply system A system is separately operated. Gas supply is performed at the gas use end, and in the gas supply system B, the liquefied gas container 11b is exchanged in step 86. If it is determined in step 87 that the exchange standard of the liquefied gas container 11b is acceptable, the process proceeds to step 88, and the gas supply is performed. System B system becomes standby.

If the separate gas supply from the gas supply system A system in step 85 is started, the process returns to the above step 72, and the gas supply system B system that has become the standby state in step 88 is in the gas supply system A system from the above step 73. When proceeding to step 74, the state is switched from the standby state to the gas supply state. Hereinafter, by repeating these steps, gas supply is continuously performed from the gas supply system A system and the B system to the gas use end.

Fig. 5 is a graph showing changes in the residual gas rate of the liquefied gas containers 11a and 11b with time passage (e.g., the number of days passed) when the gas supply is performed (Fig. 5(a)), the gas supply system A system, and the B system. The change in the gas supply pressure of the secondary side pressure of the pressure indicating regulators 13a, 13b (Fig. 5 (b)), the flow rate of the supply gas of the gas supply system A system, the B system (Fig. 53 (c)), the pressure indication The change in the valve opening degree of the valve portions 18a and 18b in the regulators 13a and 13b (Fig. 5(d)) indicates the change of each state from the step 72 in Fig. 4 .

Since the gas supply is separately performed from the gas supply system A system in a short period from the beginning, the residual gas rate of the liquefied gas container 11a gradually decreases due to the evaporation of the liquefied gas (Fig. 5(a)), but the gas supply The supply pressure of the system A system is maintained at the reference set pressure of 0.5 MPa, and the supply pressure of the gas supply system B system in standby is 0 (zero) (Fig. 5 (b)), and the gas flow rate of the gas supply system A system is used. The required 300 L/min (0 ° C, 1 atmosphere conversion value), and the gas flow rate of the gas supply system B system is 0 (zero) (Fig. 5 (c)). Further, the degree of opening of the valve portion 18a in the pressure indicating regulator 13a of the gas supply system A is gradually increased as the amount of evaporation due to the decrease in the residual gas rate of the liquefied gas container 11a is decreased, and the gas supply system B is increased. The opening of the valve portion 18b of the pressure regulating valve 13b of the system is 0 (zero) (Fig. 5(d)).

When the time elapses and the residual gas rate of the liquefied gas container 11a becomes 30% or less (elapsed time 7), the pressure of the gas supply system A system indicates that the valve portion 18a in the regulator 13a becomes 100% (full open state), and borrows When the automatic opening and closing valve 14b is opened, the supply of gas evaporated by the liquefied gas container 11b of the gas supply system B system is started, and the state is supplied in parallel (step 74). At this time, the supply pressure of the gas supply system A system is temporarily raised to the reference set pressure by 0.5 MPa or more by the valve portion 18a being fully open.

In the parallel supply state, the residual gas ratio of the two liquefied gas containers 11a and 11b is lowered by evaporation of the liquefied gas. The supply pressure of the gas supply system A system is a pressure of 0.5 MPa or more immediately after the parallel supply is started, and the amount of evaporation due to a decrease in the residual gas rate of the liquefied gas container 11a is reduced. The supply pressure is slowly decreasing. On the other hand, the supply pressure of the gas supply system B system is maintained at the reference set pressure of 0.5 MPa by the pressure indicating regulator 13b. As the amount of liquefied gas vaporization of the gas supply system A system decreases, the gas flow rate of the gas supply system A system gradually decreases, and the gas flow rate of the gas supply system B system gradually increases, so that the gas flow rate and gas supply of the gas supply system A system are increased. The sum of the gas flows of the system B system became 300 L/min.

When the residual gas rate of the liquefied gas container 11a is 3% or less (elapsed time 12) due to the passage of the time in the parallel supply state, the automatic opening and closing valve 14a of the gas supply system A system is closed, and the system from the gas supply system A is stopped. The gas supply (step 76) becomes a separate supply from the gas supply system B system (step 77). When the residual gas rate from the supply of the gas supply system B to the liquefied gas container 11b is 30% or less, the liquefied gas container 11a of the gas supply system A system is exchanged, and the residual gas rate of the liquefied gas container 11a becomes 100. % becomes the standby state (elapse time 14, step 80).

After that, when the residual gas rate of the liquefied gas container 11b is 30% or less, the gas supply system A system and the gas supply system B are connected in parallel (elapse time 18, step 82), and the residual gas of the liquefied gas container 11b. When the rate is 3% or less, it becomes a separate supply of the gas supply system A system (elapse time 23, step 85). The residual gas rate of the liquefied gas containers 11a and 11b, the supply pressure of the gas supply system A system, the B system, the flow rate and pressure of the gas supply system A system, and the B system during the continuous supply of gas in the order shown in FIG. The opening degree of the valve indicating the valve portions 18a, 18b in the regulators 13a, 13b is as shown in Fig. 5. The same change is repeated by the gas supply system A system and the B system due to the passage of time, thereby using the gas. The continuous supply flow rate was controlled to 300 L/min, and the liquefied gas in the liquefied gas containers 11a and 11b was used until the residual gas rate became 3%.

In the gas supply method according to the second aspect, the valve portions 18a and 18b of the pressure indicating regulators 13a and 13b are fully opened after the parallel supply is started, thereby temporarily improving the use. In the same manner as the liquefied gas supply device shown in FIG. 1, the pressure of the end gas supply path 15 is provided in the gas supply path of the gas supply system A and the B system, and the pressure regulator 17 is provided to supply the gas. The pressure of the gas at the end is adjusted to a pressure required for the gas use end which is lower than the reference set pressure of 0.5 MPa, whereby the pressure fluctuation or the flow rate fluctuation of the supply gas can be prevented. Further, in the first embodiment of the gas supply method, the pressure regulator 17 may be provided before the use end gas path 15, and when such a pressure regulator is incorporated into the device at the gas use end, it may be omitted. A pressure regulator 17 of the end gas supply path 15 is used.

FIG. 2 showing the first embodiment of the method of the present invention and the flowchart shown in FIG. 4 showing the second embodiment of the method of the present invention automatically supply gas from the parallel when the residual gas ratio is 3% or less. Switching to a separate state and exchanging the liquefied gas container, but when the residual gas rate is 30% or less and parallel supply, for example, an alarm or the like is output, and the gas supply is artificially switched from the parallel state to the individual state, and liquefaction is performed. Exchange of gas containers.

In the above, the gas supply system is described as an example of two systems. The gas supply system may be similarly performed in three or more systems. For example, in the gas supply of the first system, the second system may be used as the first system. In the standby state, the third system is in the second standby state, and when switching to the gas supply from the second system, the third system is in the first standby state, and the first system is in the second standby state, whereby the exchange liquefaction can be extended. The time of the gas container can increase the elongation of the liquefied gas supply device. In addition, when the gas supply system is three or more systems, the first system having a low residual gas rate can be in the first gas supply state, and the second system having a high residual gas rate can be in the second gas supply state, and the third system can become the third system or less. In the standby state, when the first system performs the container exchange and is in the standby state, the second system having the low residual gas rate is in the first gas supply state, and the third system having the high residual gas rate is in the second gas supply state. A large amount of gas is supplied by such setting.

Further, the type of the liquefied gas is not particularly limited, and the means for detecting the amount of liquefied gas in the liquefied gas container is not limited to a weight meter, and any one may be used as long as it can detect the amount of liquefied gas in the liquefied gas container. Various liquid level gauges can also be used. Further, the amount of liquefied gas in the liquefied gas container can be indirectly detected using a pressure gauge. In addition, the second set pressure with respect to the reference set pressure may be set according to the type of the gas, the supply pressure, the supply amount, and the like, and may be set to a pressure at which the parallel supply is possible. Further, the value of the residual gas rate for switching the supply state may be appropriately set depending on the type of the gas, the supply pressure, and the supply amount. In addition, the liquefied gas container may be added to the liquefied gas container to promote the evaporation of the liquefied gas within the range permitted by the decree (generally, Article 60 of the Japanese High Pressure Gas Security Code).

11a, 11b. . . Liquefied gas container

12a, 12b. . . Weight meter

13a, 13b. . . Pressure indicator regulator

14a, 14b. . . Automatic opening and closing valve

15. . . End gas supply path

16. . . Control means

17. . . Pressure regulator

18a, 18b. . . Valve department

19a, 19b. . . Pressure detection department

Fig. 1 is a system diagram showing an embodiment of a liquefied gas supply device of the present invention.

Fig. 2 is a flow chart showing a first embodiment of the liquefied gas supply method of the present invention.

FIG. 3 is an explanatory view showing changes in the state of the residual gas rate, the supply pressure, the flow rate, and the state of the pressure regulating valve in the liquefied gas container during gas supply in the first embodiment of the method of the present invention.

Fig. 4 is a flow chart showing a second embodiment of the liquefied gas supply method of the present invention.

FIG. 5 is an explanatory view showing changes in the state of the residual gas rate, the supply pressure, the flow rate, and the state of the pressure regulating valve in the liquefied gas container during gas supply in the second embodiment of the method of the present invention.

11a, 11b. . . Liquefied gas container

12a, 12b. . . Weight meter

13a, 13b. . . Pressure indicator regulator

14a, 14b. . . Automatic opening and closing valve

15. . . End gas supply path

16. . . Control means

17. . . Pressure regulator

18a, 18b. . . Valve department

19a, 19b. . . Pressure detection department

Claims (5)

A liquefied gas supply device that evaporates a liquefied gas filled in a plurality of liquefied gas containers to supply a gas use end, and includes a liquefied gas container connected to a plurality of gas supply systems; and a liquefied gas amount detection The method respectively detects the amount of liquefied gas in each liquefied gas container; the pressure adjusting means are respectively disposed in each gas supply system to adjust the pressure on the secondary side; and the gas supply blocking means are respectively disposed in each gas supply system; And using the end gas supply path, the gas supplied from the plurality of gas supply systems is confluent and supplied to the gas use end; each gas supply system is provided with a control means for liquefied gas detected by the liquefied gas amount detecting means The amount of the liquefied gas in the container is controlled by the pressure on the secondary side of the pressure adjusting means to one of a plurality of predetermined setting pressures, and the gas supply blocking means and the setting provided in the gas supply system are respectively provided. The above gas supply blocking means for other gas supply systems Switching control line. The liquefied gas supply device according to claim 1, wherein the pressure adjusting means is a pressure regulating valve that adjusts a pressure of a secondary side by adjusting an area of a flow path through which a gas flows by a valve opening degree. A method for supplying a liquefied gas by continuously supplying a gas to the gas use end using the liquefied gas supply device of the first aspect of the patent application, wherein the control means opens the first gas supply provided in the first gas supply system The first liquefied gas detected by the first liquefied gas amount detecting means when the gas is supplied from the first liquefied gas container when the secondary side setting pressure of the first pressure adjusting means is set to the reference set pressure. When the amount of the liquefied gas in the container is lower than the preset first residual gas amount setting value, the secondary side setting pressure of the first pressure adjusting means is set to a pressure higher than the reference set pressure, and the opening is set to the second. The second gas supply blocking means of the gas supply system supplies the gas in parallel from both the first gas supply system and the second gas supply system. A method of supplying a liquefied gas by continuously supplying a gas to the gas use end using the liquefied gas supply device of the second aspect of the patent application, wherein the control means opens the first gas supply provided in the first gas supply system The first liquefied gas detected by the first liquefied gas amount detecting means when the gas is supplied from the first liquefied gas container when the secondary side setting pressure of the first pressure regulating valve is set to the reference set pressure. When the amount of the liquefied gas in the container is lower than the preset first residual gas amount setting 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. 1 Gas supply is performed in parallel with both the gas supply system and the second gas supply system. The method of supplying a liquefied gas according to the third or fourth aspect of the invention, wherein the amount of the liquefied gas in the first liquefied gas container detected by the first liquefied gas amount detecting means is lower than the first When the second residual gas amount setting value of the liquefied gas amount having a small residual gas amount setting value is set, the first gas supply blocking means is turned off, the gas supply from the first gas supply system is stopped, and the second gas supply system is switched from the second gas supply system. Gas supply.