JP2019132371A - Liquefied gas supply apparatus and liquefied gas supply method - Google Patents

Abstract

To provide a liquefied gas supply apparatus and a liquefied gas supply method capable of surely preventing liquefied gas to be supplied to the outside from being re-liquefied in a supply process without consuming excessive energy for heating the liquefied gas.SOLUTION: A liquefied gas supply apparatus includes: a liquefied gas supply line 3 for supplying liquefied gas G to the outside; a heater 8 for heating the liquefied gas G flowing through the liquefied gas supply line 3; a manometer 6 and a thermometer 5 installed in the path of the liquefied gas supply line 3; and a heater control unit 4 for setting a heating temperature generated by the heater 8 on the basis of the internal pressure of a liquefied gas vessel 1 detected by the manometer 6 and the temperature of the liquefied gas G or of any one portion of the surface of the gas supply line detected by the thermometer 5, such that the temperature of the liquefied gas G flowing through the liquefied gas supply line 3 is kept at a temperature higher than a re-liquefaction temperature of the liquefied gas G under the internal pressure within the liquefied gas vessel 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquefied gas supply apparatus and a liquefied gas supply method.

  Conventionally, liquefied gases such as ammonia and hydrogen chloride have been used as raw materials for semiconductors, liquid crystal panels, and photovoltaic power generation panels. Generally, these liquefied gases are filled in a metal container in a liquid state (liquid phase), and stored and distributed in a gas-liquid mixed state (gas phase and liquid phase). Usually, when supplying these liquefied gases to the outside, a manufacturing apparatus using the liquefied gas, for example, a semiconductor, a liquid crystal panel, and a solar cell as described above, is drawn out in a gaseous state from a gas phase portion in a container. Supplied to device manufacturing equipment that manufactures thin films such as photovoltaic panels. Further, when the gas pressure in the container is lowered, that is, when the gas in the gas phase part is reduced, vaporized gas is generated from the liquid phase part and replenished by heating the container from the outside.

  In a liquefied gas supply apparatus such as a cylinder cabinet that supplies a high-pressure liquefied gas as described above, a liquefied gas supply line has been conventionally used in order to prevent the liquefied gas from being reliquefied in the liquefied gas supply line. A configuration is employed in which the liquefied gas is heated by a heater and held at a temperature higher than the reliquefaction temperature. The set temperature (heating temperature) of the heater is determined in consideration of the worst condition, that is, the condition that facilitates re-liquefaction, taking into account the design flow rate of the liquefied gas, the environmental temperature, and the like. It is set to be heated at a fixed temperature (see, for example, Patent Documents 1 and 2).

JP 2006-283812 A Japanese Patent Publication No. 6-33858

  However, in the conventional liquefied gas supply apparatus as shown in Patent Documents 1 and 2, as described above, the set temperature when heating the liquefied gas is set in consideration of the conditions that are most likely to reliquefy. Therefore, it is set to a constant temperature so that it is always heated at a high temperature under any conditions. For this reason, even when the actual condition is a condition that does not require a high temperature setting, since the liquefied gas is constantly heated at a relatively high constant temperature, the amount of heat released from the heater also increases and wasteful power is consumed. Etc. had occurred. In particular, when a liquefied gas supply apparatus is installed in a large-scale factory or the like, the number of installed liquefied gas supply apparatuses increases. Therefore, improvement has been desired from the viewpoint of energy saving and reduction in manufacturing cost.

  The present invention has been made in view of the above problems, and does not consume excessive energy for heating the liquefied gas supplied to the outside, and reliably prevents the liquefied gas from being reliquefied during the supply process. It is an object of the present invention to provide a liquefied gas supply apparatus and a liquefied gas supply method capable of performing the above.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that the liquid phase part accommodated in the liquefied gas container is vaporized to cause a phase transition to the gas phase part, and the gas phase part is pressurized to increase the gaseous state. A liquefied gas supply device for supplying liquefied gas to the outside, wherein one end side of the liquefied gas container is connected to the liquefied gas container, and the liquefied gas is supplied to the outside. A pressure reducing valve for reducing the pressure of the liquefied gas, and provided in at least part of a path between the liquefied gas container and the pressure reducing valve in the gas supply line, and circulates through the gas supply line A heater that heats the liquefied gas; a pressure detection unit that is provided in the vicinity of the outlet side of the liquefied gas container in the path of the gas supply line; and that detects an internal pressure of the liquefied gas container; A temperature detection unit that is provided in the vicinity of the primary side of the pressure reducing valve in the passage and detects the temperature of at least one of the liquefied gas flowing through the gas supply line or the surface of the gas supply line; and the pressure detection The gas supply line is controlled based on the internal pressure of the liquefied gas container detected by the unit and the temperature of the liquefied gas detected by the temperature detection unit or the surface of the gas supply line. A heater controller configured to set a heating temperature by the heater so as to maintain a temperature of the liquefied gas flowing at a temperature higher than a reliquefaction temperature of the liquefied gas under an internal pressure of the liquefied gas container. This is a liquefied gas supply device.

  Further, in the invention according to claim 2, the heater control unit is configured to respond to a change in temperature of at least one of the internal pressure of the liquefied gas container and / or the surface of the liquefied gas or the gas supply line. The liquefied gas supply device according to claim 1, wherein the heating temperature is set while constantly changing the heating temperature by the heater.

  The invention according to claim 3 is characterized in that by heating the liquefied gas container, the liquid phase part accommodated in the liquefied gas container is vaporized to cause a phase transition to the gas phase part. The liquefied gas supply apparatus according to claim 1 or claim 2.

  According to a fourth aspect of the present invention, the liquid phase portion accommodated in the liquefied gas container is vaporized to cause a phase transition to the gas phase portion, and the gas phase portion is pressurized to bring the gaseous liquefied gas to the outside. A liquefied gas supply method for supplying the liquefied gas in a gaseous state in the liquefied gas container, and supplying the liquefied gas to the outside by a liquefied gas supply line having one end connected to the liquefied gas container; The internal pressure of the liquefied gas container and the temperature of at least one of the liquefied gas in the liquefied gas supply line or the surface of the gas supply line are detected, and the internal pressure of the liquefied gas container and the liquefied gas are detected. Heating the liquefied gas flowing through the gas supply line while setting a heating temperature based on the temperature of the gas or at least one of the surfaces of the gas supply line And by the temperature of the liquefied gas, a liquefied gas supply wherein the holding the temperature higher than the liquefaction temperature of the liquefied gas in the interior pressure of the liquefied gas container.

  According to a fifth aspect of the present invention, the gas supply line is always in accordance with an internal pressure of the liquefied gas container and / or a temperature change of at least one of the surface of the liquefied gas or the gas supply line. The liquefied gas supply method according to claim 4, wherein the heating temperature is set while changing the heating temperature of the liquefied gas flowing through the gas.

  The invention according to claim 6 is characterized in that by heating the liquefied gas container, the liquid phase part accommodated in the liquefied gas container is vaporized to cause a phase transition to the gas phase part. The liquefied gas supply method according to item 4 or claim 5.

According to the liquefied gas supply device of the present invention, the internal pressure of the liquefied gas container detected by the pressure detector and the temperature of the liquefied gas detected by the temperature detector or the surface of the gas supply line are at least one of the temperatures. Based on this, by controlling the current applied to the heater, the temperature of the liquefied gas flowing through the gas supply line is maintained at a temperature higher than the reliquefaction temperature of the liquefied gas under the internal pressure of the liquefied gas container. The structure provided with the heater control part which sets the heating temperature by a heater is employ | adopted.
That is, by controlling the current applied to the heater so that the liquefied gas can be heated to a temperature that does not re-liquefy according to the internal pressure of the liquefied gas container, the heating temperature of the liquefied gas can be controlled by the air conditioning equipment. It is possible to automatically set an appropriate temperature without being influenced by the presence or absence, seasonal temperature fluctuations, and the like.
Therefore, it is possible to reliably prevent the liquefied gas from being liquefied again during the supply process without consuming excessive energy for heating the liquefied gas supplied to the outside.

Further, according to the liquefied gas supply method of the present invention, as described above, the internal pressure of the liquefied gas container and the temperature of at least one of the liquefied gas in the liquefied gas supply line or the surface of the gas supply line are detected. By heating the liquefied gas flowing through the gas supply line while setting the heating temperature based on the internal pressure and the temperature of the liquefied gas, the temperature of the liquefied gas is changed to the liquefied gas under the internal pressure of the liquefied gas container. A method of keeping the temperature higher than the reliquefaction temperature is adopted.
As a result, as described above, the heating temperature of the liquefied gas can be automatically set at an appropriate temperature that does not reliquefy in accordance with the internal pressure of the liquefied gas container.
Accordingly, as described above, it is possible to reliably prevent the liquefied gas from being reliquefied during the supply process without consuming excessive energy for heating the liquefied gas.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates typically the liquefied gas supply apparatus and liquefied gas supply method which are embodiment to which this invention is applied, and is the schematic which shows the whole structure of a liquefied gas supply apparatus. It is a figure explaining an example which sets the heating temperature of the liquefied gas by a heater using the liquefied gas supply apparatus and liquefied gas supply method which are the embodiments to which the present invention is applied. It is the graph which showed the saturated vapor pressure curve showing the relationship with liquefaction temperature, and the heating temperature curve showing the relationship between the internal pressure of a liquefied gas container, and the heating temperature of liquefied gas.

  Hereinafter, a liquefied gas supply apparatus and a liquefied gas supply method according to an embodiment to which the present invention is applied will be described with reference to the drawings as appropriate. In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent. In addition, the materials and the like exemplified in the following description are examples, and the present invention is not limited to them, and can be appropriately modified and implemented without changing the gist thereof.

[Liquefied gas supply equipment]
Hereinafter, a liquefied gas supply apparatus according to an embodiment to which the present invention is applied will be described in detail with reference to FIGS. 1 and 2.
FIG. 1 is a schematic diagram showing the overall configuration of a liquefied gas supply apparatus 10 used in the present embodiment, and FIG. 2 shows a heater 7 in the liquefied gas supply method using the liquefied gas supply apparatus 10 shown in FIG. FIG. 6 is a diagram for explaining an example of setting the heating temperature of the liquefied gas G by means of a saturated vapor pressure curve representing the relationship between the internal pressure P of the liquefied gas container 1 and the reliquefaction temperature T of the liquefied gas G; It is the graph which showed the heating temperature curve (heating temperature HT curve) showing the relationship between the internal pressure P of this, and the heating temperature HT of the liquefied gas G.

As shown in FIG. 1, the liquefied gas supply apparatus 10 used in this embodiment includes a liquefied gas container 1, a container valve 2, a liquefied gas supply line 3, a heater controller 4, a thermometer (temperature detector). ) 5, a pressure gauge (pressure detection unit) 6, a container heating unit 7, a heater 8, and a pressure reducing valve 9.
For example, the liquefied gas supply device 10 heats the surface of the liquefied gas container 1 with the container heating unit 6, thereby vaporizing the liquid phase part accommodated in the liquefied gas container 1 and causing phase transition to the gas phase part. This is a device for boosting the gas phase and supplying the gaseous liquefied gas G to the outside through the liquefied gas supply line 3.

  More specifically, the liquefied gas supply device 10 includes a liquefied gas supply line 3 that is connected to the liquefied gas container 1 at one end 3a side and supplies the liquefied gas G to the outside. A pressure reducing valve 9 for reducing the pressure of the liquefied gas G is provided therein. The liquefied gas supply line 3 is provided with a heater 8 for heating the liquefied gas G flowing through the liquefied gas supply line 3 in at least a part of the path between the liquefied gas container 1 and the pressure reducing valve 9. . Further, in the path of the liquefied gas supply line 3, a pressure gauge 6 provided in the vicinity of the outlet 1 a side of the liquefied gas container 1 for detecting the internal pressure P of the liquefied gas container 1 and the vicinity of the primary side 9 a of the pressure reducing valve 9. And a thermometer 5 capable of detecting the temperature of at least one of the liquefied gas G flowing through the liquefied gas supply line 3 or the surface of the liquefied gas supply line 3.

  The liquefied gas supply device 10 of the present embodiment is configured so that the heater 8 is based on the internal pressure P of the liquefied gas container 1 detected by the pressure gauge 6 and the temperature T of the liquefied gas G detected by the thermometer 5. By controlling the current A applied to the liquefied gas G, the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is set to a temperature higher than the reliquefaction temperature RT of the liquefied gas G under the internal pressure P of the liquefied gas container 1. A heater control unit 4 for setting the heating temperature HT by the heater 8 is provided so as to be held.

  In the liquefied gas supply device 10, although not shown in FIG. 1, a liquid phase (liquid phase portion) always exists in the liquefied gas container 1 from the start of supply of the liquefied gas to the stop of supply. The phase range, the range that always includes the gas phase from the start of supply of the liquefied gas to the stop of supply, and at least a part of the phase transition from the liquid phase to the gas phase as the supply of the liquefied gas proceeds A range exists. In the liquefied gas supply device 10, when the range of the liquid phase in the liquefied gas container 1 becomes below a certain level, it is determined that the liquefied gas container 1 has reached the replacement time, and the interior is filled with the liquid phase portion. The new liquefied gas container 1 can be exchanged for use.

The liquefied gas container 1 is a container for filling liquefied gas. Although it does not specifically limit as a material of the liquefied gas container 1, Specifically, stainless steel (SUS), manganese steel etc. are mentioned, for example.
Although it does not specifically limit as liquefied gas with which the liquefied gas container 1 is filled, Specifically, ammonia, hydrogen chloride, chlorine, nitrous oxide etc. are mentioned, for example.

The container valve 2 is a valve attached to the outlet 1a of the liquefied gas container 1, and the supply of the liquefied gas to the outside can be controlled by opening and closing the valve.
The container valve 2 is not particularly limited, but generally a ball valve is used.

  In addition, although illustration is abbreviate | omitted in FIG. 1, the container valve 2 is provided so that it may always be connected to the range in the liquefied gas container 1 including the gaseous-phase part. It should be noted that such a portion of the liquefied gas container 1 that always includes the gas phase portion is regulated by law so as to have a temperature of 40 ° C. or lower.

  As described above, the liquefied gas supply line 3 is a pipe connected to the liquefied gas container 1 at the one end 3a side and supplying the liquefied gas G to the outside. In the illustrated example, the one end 3a is connected to the container valve 2. Via the outlet 1a of the liquefied gas container 1. The liquefied gas supply line 3 in the illustrated example is provided with a pressure gauge 6, a thermometer 5, and a pressure reducing valve 9 in that order in order to supply the liquefied gas G from the other end 3 b to the outside. ing. In addition, a heater 8 to be described in detail later is attached to at least a part of a path between the liquefied gas container 1 and the pressure reducing valve 9 in the liquefied gas supply line 3. In the illustrated example, a pressure gauge in the path is provided. A heater 8 is provided from 6 to the pressure reducing valve 9.

  The material of the piping constituting the liquefied gas supply line 3 is not particularly limited, and can be appropriately selected in consideration of resistance to the liquefied gas flowing through the inside.

  As described above, the heater control unit 4 sets the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 to be higher than the reliquefaction temperature RT of the liquefied gas G under the internal pressure P detected by the pressure gauge 6. The heating temperature HT by the heater 8 is set so as to maintain a high temperature.

  Specifically, a measured value signal of the temperature T of the liquefied gas G detected by a thermometer 5 to be described in detail later is input to the heater control unit 4 via a signal line C1 and detected by the pressure gauge 6. The measured value signal of the internal pressure P of the liquefied gas container 1 is input via the signal line C2. The heater control unit 4 is connected to the heater 8 via a signal line C3.

  The heater control unit 4 controls the current A applied to the heater 8 via the signal line C3 based on the temperature T of the liquefied gas G and the internal pressure P of the liquefied gas container 1, although details will be described later. Or control voltage pulses. Accordingly, the heater control unit 4 sets the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 to a temperature higher than the reliquefaction temperature RT of the liquefied gas G under the internal pressure P detected by the pressure gauge 6. The heating temperature HT by the heater 8 is set so as to be held at

  Although it does not specifically limit as the heater control part 4, For example, a programmable logic controller (PLC) etc. can be used.

  As described above, the thermometer 5 is provided in the vicinity of the primary side 9 a of the pressure reducing valve 9 in the path of the liquefied gas supply line 3. In this embodiment, the thermometer 5 detects the temperature T of the liquefied gas G sent out from the liquefied gas container 1 and flowing through the liquefied gas supply line 3, for example. Since the thermometer 5 in this embodiment needs to detect the temperature T of the liquefied gas G before it is adiabatically expanded due to reduced pressure, it is provided in the vicinity of the primary side 9a of the pressure reducing valve 9 in the path of the liquefied gas supply line 3. It has been.

  The measurement value signal of the temperature T of the liquefied gas G detected by the thermometer 5 is transmitted to the heater control unit 4 via the signal line C1 as described above. And the heater control part 4 performs the process based on the measured value signal transmitted from the thermometer 5 and the pressure gauge 6 mentioned later as mentioned above, and sets the heating temperature HT of the liquefied gas G. FIG.

The thermometer 5 is not particularly limited, and for example, a T-type thermocouple can be used.
Moreover, although the installation position of the thermometer 5 shown in FIG. 1 is set in the vicinity of the primary side 9a of the pressure reducing valve 9 in the path of the liquefied gas supply line 3, it is not limited to this. The installation position of the thermometer 5 can be appropriately changed between the pressure gauge 6 and the pressure reducing valve 9 in the path of the liquefied gas supply line 3, for example.
A plurality of thermometers 5 may be provided between the pressure gauge 6 and the pressure reducing valve 9 in the path of the liquefied gas supply line 3. In this case, an average value of detection values in the plurality of thermometers 5 may be transmitted to the heater control unit 4 as a measurement value signal.

  As described above, the pressure gauge 6 is provided in the vicinity of the outlet 1 a side of the liquefied gas container 1 in the path of the liquefied gas supply line 3. Moreover, since the pressure gauge 6 detects the internal pressure P of the liquefied gas container 1, it is provided in the position as close as possible to the exit 1a of the liquefied gas container 1 like the example shown in FIG.

  The measurement value signal of the internal pressure P of the liquefied gas container 1 detected by the pressure gauge 6 is transmitted to the heater control unit 4 via the signal line C2 as described above. The heater control unit 4 performs processing based on the measurement value signal transmitted from the thermometer 5 and the pressure gauge 6 and sets the heating temperature HT of the liquefied gas G.

  As the pressure gauge 6, a pressure sensor or the like conventionally used for detecting internal pressure such as a gas cylinder can be used without any limitation.

  The container heating unit 7 heats the liquefied gas in the liquid state accommodated in the liquefied gas container 1 by temperature control by a container temperature control unit (not shown), thereby sequentially evaporating the liquefied gas in the liquid phase. Phase transition to the liquefied gas G of the phase. The container heating unit 7 in the illustrated example is provided so as to cover the surface of the region below the approximate center in the longitudinal direction of the liquefied gas container 1.

The container heating unit 7 is not particularly limited as long as the surface of the liquefied gas container 1 can be heated. Specifically, for example, a pipe for circulating a heat exchange medium wound around the surface of the liquefied gas container 1 may be used. Specific examples of the heat exchange medium include gaseous media such as hot air and hot air, or liquid media such as hot water, hot water, and hot oil.
Further, the container heating unit 7 may have a configuration in which heat is directly transmitted to the container surface by a method of transmitting heat by infrared rays using a halogen heater or the like, or an electric heater or the like.

  As described above, the heater 8 is provided in at least a part of the path between the liquefied gas container 1 and the pressure reducing valve 9 in the liquefied gas supply line 3. In the example shown in FIG. 1, the outlet of the liquefied gas container 1 is provided. The pressure reducing valve 9 is provided from the vicinity of 1a. The heater 8 heats the liquefied gas G flowing through the liquefied gas supply line 3. The heater 8 includes, for example, an electric heater and can be configured to be wound around the liquefied gas supply line 3.

  In the present embodiment, the heater 8 is composed of an electric heater or the like, and the heater control unit 4 controls the current A applied to the heater 8. However, the present invention is not limited to this. As the heater 8, for example, a method of transferring heat by infrared rays using a halogen heater or the like may be employed.

  Furthermore, the heater 8 may be configured by, for example, a pipe wound around the surface of the liquefied gas supply line 3 for circulating a heat exchange medium. Examples of the heat exchange medium in this case include a gaseous medium such as warm air and hot air, or a liquid medium such as warm water, hot water, and hot oil. In such a case, the heater control unit 4 controls, for example, a set temperature (heating temperature) of a medium heating unit (not shown) for heating the heat exchange medium flowing in the pipe.

The pressure reducing valve 9 is for adiabatically expanding the pressure of the liquefied gas G by reducing the pressure of the liquefied gas G, and is provided downstream of the thermometer 5 in the path of the liquefied gas supply line 3. That is, the primary side 9a of the pressure reducing valve 9 is arranged so as to be connected to the thermometer 5 in the path of the liquefied gas supply line 3, and the secondary side 9b is connected to the liquefied gas G after the pressure reduction. It arrange | positions at the exit 3b side.
Such a pressure reducing valve 9 is not particularly limited, and those widely used in the field of liquefied gas supply devices can be employed without any limitation.

Hereinafter, in the liquefied gas supply apparatus 10 of the present embodiment, the heater control unit 4 sets the heating temperature HT for heating the vaporized gas G by the heater 8, and the temperature T of the liquefied gas G is higher than the reliquefaction temperature RT. The control for maintaining the temperature will be described more specifically.
First, a measurement value signal of the internal pressure P of the liquefied gas container 1 detected by the pressure gauge 6 is input to the heater control unit 4 via the signal line C2.
At the same time, a measured value signal of the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 detected by the thermometer 5 is input to the heater controller 4 via the signal line C1.

  Next, the heater control unit 4 calculates the reliquefaction temperature RT under the internal pressure P based on the internal pressure P of the liquefied gas container 1 and the reliquefaction data input in advance, and then heats the liquefied gas G. The temperature HT is set, and the current A applied to the heater 8 is controlled. The heating temperature HT set at this time is higher than the reliquefaction temperature RT under the internal pressure P. The reliquefaction data as described above is, for example, data indicating the relationship between the internal pressure P corresponding to the gas type and the reliquefaction temperature RT, and will be described in detail later. For example, in the graph of FIG. The data is represented by the saturated vapor pressure curve shown.

Next, the heater control unit 4 controls the current A applied to the heater 8 based on the heating temperature HT set as described above and compared with the measured value of the temperature T of the liquefied gas G detected by the thermometer 5.
As a result, when the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is lower than the set heating temperature HT, the heater control unit 4 sets the heating temperature HT by the heater 8 to the above set value. Then, the electric current A applied to the heater 8 is pulled up, and the liquefied gas G is heated at a higher temperature. Thereafter, when the temperature T of the liquefied gas G rises to a temperature higher than the set heating temperature HT, the heater control unit 4 lowers the current A applied to the heater 8 or stops it, thereby stopping the heater 8. The heating temperature HT is controlled to be lowered.
Then, when the temperature T of the liquefied gas G again becomes equal to or lower than the heating temperature HT set above, the current A applied to the heater 8 is raised again, and the liquefied gas G is supplied at the heating temperature HT set above. Control to heat.

On the other hand, when the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is higher than the set heating temperature HT, the heater control unit 4 reduces or stops the current A applied to the heater 8. By doing so, the heating temperature HT by the heater 8 is controlled to be lowered. Thereafter, when the temperature T of the liquefied gas G is lowered to the set heating temperature HT or lower, the heater control unit 4 controls to raise the heating temperature HT by increasing the current A applied to the heater 8.
When the temperature T of the liquefied gas G again becomes higher than the heating temperature HT set above, the heater control unit 4 again reduces or stops the current A applied to the heater 8. Thus, the heating temperature HT is controlled to be lowered.

  The heater control unit 4 maintains the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 at a temperature higher than the reliquefaction temperature RT by repeating the above control. That is, the temperature T of the liquefied gas G is not always heated at a constant temperature until the actual condition in the liquefied gas supply apparatus 10 is a condition that does not require a high temperature setting, but the temperature T of the liquefied gas G is changed to the reliquefaction temperature RT. The heating temperature HT by the heater 8 is controlled to such an extent that it can be maintained at a higher temperature. As a result, it is possible to prevent the electric current A applied to the heater 8 from becoming excessive and consuming unnecessary electric power, so that the liquefied gas G is supplied without consuming excessive energy for heating the liquefied gas G. It is possible to reliably prevent liquefaction during the process. In particular, when the liquefied gas supply apparatus 10 is installed in a large-scale factory or the like, the number of the installed liquefied gas supply apparatuses 10 is increased, so that a greater energy reduction effect can be obtained from the viewpoint of energy saving and manufacturing cost reduction.

  The control method based on the internal pressure P of the liquefied gas container 1 detected by the pressure gauge 6 and the temperature T of the liquefied gas G detected by the thermometer 5 is not limited to the above method. PID control for the target temperature may be performed.

  Further, in the liquefied gas supply device 10, the heater control unit 4 always applies a current to be applied to the heater 8 in accordance with the change in the internal pressure P of the liquefied gas container 1 and / or the temperature T of the liquefied gas G. It is more preferable to adopt a configuration that sets the heating temperature HT while changing the heating temperature HT by the heater 8 by controlling. As a result, the control for maintaining the temperature T of the liquefied gas G at a temperature higher than the reliquefaction temperature RT as described above can always be stably performed, so that a greater energy reduction effect can be obtained.

  In the liquefied gas supply apparatus 10 of the present embodiment having the above-described configuration, the inside of the liquefied gas container 1 heated by the container heating unit 7 at the start of the supply of the liquefied gas G is a liquid liquefied gas (liquid phase part). ). Although not shown in detail in FIG. 1, the liquid level of the liquefied gas in the liquid phase at the start of supply is located above the upper end of the container heating unit 7. The liquid-phase liquefied gas accommodated in the liquefied gas container 1 is heated by the container heating unit 7 so that the liquid-phase liquefied gas G sequentially changes into the gas-phase liquefied gas G, and then the outlet 1 a and the container valve 2. Is introduced into the liquefied gas supply line 3 and supplied to the outside.

  Thereafter, as the liquefied gas in the liquefied gas container 1 is supplied to the outside, the liquid level of the liquid phase portion (liquefied gas) in the liquefied gas container 1 is lowered. And when the liquid level of the liquid phase part in the liquefied gas container 1 falls to a predetermined position, for example, the liquefaction accommodated inside is detected by detecting the remaining amount of the liquid phase part with a weight meter (not shown). It is determined that the remaining amount of gas has decreased, and the supply of liquefied gas is stopped. Thereafter, the liquefied gas container 1 in which the remaining amount of the liquid phase portion is equal to or less than a predetermined value is removed from the liquefied gas supply device 10 and replaced with a new liquefied gas container 1.

  When a weight meter (not shown) is adopted as the liquid level detection means for the liquid phase portion of the liquefied gas, for example, a load cell or the like is used as the weight meter, and the weight of the entire liquefied gas container 1 is constantly measured to measure the internal liquid. By measuring the weight of the phase part and performing arithmetic processing, the position of the liquid surface of the liquid phase part can be detected.

  The container temperature control unit is not particularly limited as in the case of the heater control unit 4. For example, a programmable logic controller (PLC) can be used.

[Liquid gas supply method]
Next, the liquefied gas supply method of this embodiment using the liquefied gas supply apparatus 10 as described above will be described with reference to FIGS. 1 and 2.
In the liquefied gas supply method of the present embodiment, the surface of the liquefied gas container 1 is heated to vaporize the liquid phase portion accommodated in the liquefied gas container 1 to cause a phase transition to the gas phase portion. The gas is liquefied and the gaseous liquefied gas is supplied to the outside.
In addition, in the following description, the detailed description is abbreviate | omitted about the structure which overlaps with description of said liquefied gas supply apparatus 10. FIG.

In the liquefied gas supply method of the present embodiment, the liquefied gas G that has been gasified in the liquefied gas container 1 is supplied to the outside through the liquefied gas supply line 3 that is connected to the liquefied gas container 1 at one end 3a side. The internal pressure P of the liquefied gas container 1 and the temperature T of the liquefied gas G in the liquefied gas supply line 3 are detected.
In the liquefied gas supply method of the present embodiment, the liquefaction flowing through the liquefied gas supply line 3 while setting the heating temperature HT based on the internal pressure P of the liquefied gas container 1 and the temperature T of the liquefied gas G. By heating the gas G, the temperature T of the liquefied gas G is maintained at a temperature higher than the reliquefaction temperature RT of the liquefied gas G under the internal pressure P of the liquefied gas container 1.

In an example of setting the heating temperature HT of the liquefied gas G by the heater 8 in the liquefied gas supply method of this embodiment, the relationship between the internal pressure P of the liquefied gas container 1 and the reliquefying temperature RT of the liquefied gas G in FIG. And a graph showing a heating temperature curve (heating temperature HT curve) representing a relationship between the saturated vapor pressure curve representing the temperature and the internal pressure P of the liquefied gas container 1 and the heating temperature HT of the liquefied gas G (see FIG. (See also FIG. 1).
Here, the horizontal axis in FIG. 2 indicates the reliquefaction temperature RT of the liquefied gas G and the heating temperature HT of the liquefied gas G, and the vertical axis indicates the internal pressure P of the liquefied gas container 1. Further, the saturated vapor pressure curve shown in the graph of FIG. 2 represents general characteristics of various gases used as the liquefied gas. In FIG. 2, the region below the curve is the gas phase region. Yes, the curve and the region above the curve are the liquid phase region.

  In the saturated vapor pressure curve shown in the graph of FIG. 2, the reliquefaction temperature RT of the liquefied gas G is RT4 (° C.) when the internal pressure P of the liquefied gas container 1 is P4 (Pa), and the internal pressure When P is P3 (Pa) lower than P4 (Pa), RT3 (° C) is lower than RT4 (° C). Further, in FIG. 2, the reliquefaction temperature RT of the liquefied gas G is RT2 (° C.) when the internal pressure P of the liquefied gas container 1 is P2 (Pa) lower than P3 (Pa). When the pressure P is P1 (Pa) lower than P2 (Pa), RT1 (° C) is lower than RT2 (° C).

That is, the relationship between the internal pressure P (Pa) of the liquefied gas container 1 and the heating temperature HT (° C.) of the liquefied gas G to be set based on the saturated vapor pressure curve shown in the graph of FIG. Similarly, it is represented by the heating temperature curve (heating temperature HT curve) shown in the graph of FIG. 2, and can be represented by the following formulas (1) to (4).
P <P1: HT <HT1 (1)
P1 ≦ P <P2: HT1 ≦ HT <HT2 (2)
P2 ≦ P <P3: HT2 ≦ HT <HT3 (2)
P3 ≦ P: HT3 ≦ HT <HT4 (4)
In the above formulas (1) to (4), P, P1, P2, P3: internal pressure (internal pressure of the liquefied gas container), HT, HT1, HT2, HT3, HT4: heating temperature (liquefied gas supply line The temperature at which the liquefied gas flowing is heated).

  In the liquefied gas supply method of this embodiment, the reliquefaction temperature RT of the liquefied gas G is calculated based on the internal pressure P of the liquefied gas container 1, the heating temperature HT of the liquefied gas G is set, and the heater 8 is set. The applied current A is controlled. That is, for example, when the internal pressure P of the liquefied gas container 1 is P3 (Pa) or higher, the heating temperature HT3 of the liquefied gas G is set at a temperature higher than RT3 (° C.). When the internal pressure P of the liquefied gas container 1 is in the range of P1 to P2 (Pa), the heating temperature HT1 of the liquefied gas G is set in a range higher than RT1 and not higher than RT2 (° C.). To do.

In the present embodiment, the current A applied to the heater 8 is controlled based on the heating temperature HT set above and compared with the measured value of the temperature T of the liquefied gas G detected by the thermometer 5.
Specifically, when the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is lower than the set heating temperature HT, that is, not more than the re-liquefying temperature RT calculated above, the heating temperature by the heater 8 The current A applied to the heater 8 is raised so that HT becomes the above set value. Thereafter, when the temperature T of the liquefied gas G rises to a temperature higher than the set heating temperature HT, the current A applied to the heater 8 is reduced or stopped to lower the heating temperature HT by the heater 8. Control to do.
Then, when the temperature T of the liquefied gas G again becomes equal to or lower than the heating temperature HT set above, the current A applied to the heater 8 is raised again, and the liquefied gas G is supplied at the heating temperature HT set above. Control to heat.

On the other hand, when the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is higher than the set heating temperature HT, the current A applied to the heater 8 is reduced or stopped to thereby stop the heater 8. The heating temperature HT is controlled to be lowered. Thereafter, when the temperature T of the liquefied gas G falls below the set heating temperature HT, the current A applied to the heater 8 is raised to control the heating temperature HT to be higher.
Then, when the temperature T of the liquefied gas G is again higher than the heating temperature HT set above, the current A applied to the heater 8 is again reduced or stopped so that the heating temperature Control to lower HT.

  In the liquefied gas supply method of this embodiment, the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is maintained at a temperature higher than the reliquefaction temperature RT by repeating the above control. Thereby, as described above, it is possible to prevent the electric current A applied to the heater 8 from being excessive and consuming unnecessary electric power, and without consuming excessive energy for heating the liquefied gas G and liquefying. It is possible to reliably prevent the gas G from being reliquefied during the supply process.

  From the viewpoint of handling and safety of the liquefied gas container 1, in normal actual use, for example, the internal pressure P of the liquefied gas container 1 shown in the saturated vapor pressure curve shown in the graph of FIG. The area below P3 (Pa) is the regular area.

  In the liquefied gas supply method of the present embodiment, the liquefied gas G flowing through the liquefied gas supply line 3 is constantly changed according to the change in the internal pressure P of the liquefied gas container 1 and / or the temperature T of the liquefied gas G. It is more preferable to set while changing the heating temperature HT. As a result, the control for maintaining the temperature T of the liquefied gas G at a temperature higher than the reliquefaction temperature RT as described above can always be stably performed, so that a greater energy reduction effect can be obtained.

<Effect>
As described above, according to the liquefied gas supply device 10 of the present embodiment, the internal pressure P of the liquefied gas container 1 detected by the pressure gauge 6 and the temperature T of the liquefied gas G detected by the thermometer 5. By controlling the current A applied to the heater 8 based on the above, the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3 is changed to the reliquefaction temperature of the liquefied gas G under the internal pressure P of the liquefied gas container 1. A configuration provided with a heater control unit 4 that sets a heating temperature HT by the heater 8 so as to be held at a temperature higher than RT is adopted. That is, the heating temperature of the liquefied gas G is controlled by controlling the current applied to the heater 8 so that the liquefied gas G can be heated to a temperature at which the liquefied gas G is not re-liquefied according to the internal pressure P of the liquefied gas container 1. It is possible to automatically set HT to an appropriate temperature without being affected by the presence or absence of air conditioning equipment, seasonal temperature fluctuations, and the like. Therefore, it is possible to reliably prevent the liquefied gas G from being reliquefied during the supply process without consuming excessive energy for heating the liquefied gas G supplied to the outside.

  Further, according to the liquefied gas supply method of the present embodiment, as described above, the internal pressure P of the liquefied gas container 1 and the temperature T of the liquefied gas G in the liquefied gas supply line 3 are detected, and these internal pressures P And by setting the heating temperature HT based on the temperature T of the liquefied gas G, by heating the liquefied gas G flowing through the liquefied gas supply line 3, the temperature T of the liquefied gas G is changed to the inside of the liquefied gas container 1. A method is employed in which the temperature is maintained at a temperature higher than the reliquefaction temperature RT of the liquefied gas G under the pressure P. Thereby, similarly to the above, according to the internal pressure P of the liquefied gas container 1, it becomes possible to automatically set the heating temperature HT of the liquefied gas G at an appropriate temperature without reliquefaction. Therefore, as described above, it is possible to reliably prevent the liquefied gas G from being reliquefied during the supply process without consuming excessive energy for heating the liquefied gas G.

<Modification of the present invention>
Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. It is possible to apply.
For example, in the present embodiment, the liquefied gas supply line 3 is further divided into a plurality of heating regions in the length direction, and a plurality of heaters are provided corresponding to the respective heating regions. You may employ | adopt the structure which performs the temperature control optimized for every site | part of the length direction, respectively.

  Further, in the example described in the present embodiment, the heating temperature control by the heater 8 is performed by raising or lowering the current A applied to the heater 8, but the present invention is not limited to this. You may carry out by controlling the pulse voltage applied to No.8.

  In the present embodiment, the temperature detected by the thermometer 5 is the temperature T of the liquefied gas G flowing through the liquefied gas supply line 3, but is not limited to this. For example, the temperature of the surface of the liquefied gas supply line 3, that is, the surface of the pipe is detected by the thermometer 5, and this value is transmitted to the heater control unit 4 to control the heating temperature HT of the liquefied gas G by the heater 8. It is good also as composition which performs. Thus, the thermometer 5 can be made into a simple structure by making the temperature measured with the thermometer 5 into the temperature of the piping surface of the liquefied gas supply line 3.

  For example, if the temperature of the piping surface of the liquefied gas supply line 3 is higher than the reliquefaction temperature RT under the pressure detected by the pressure gauge 6, the heat from the liquefied gas G is not released to the outside. There is no liquefaction. Therefore, even when the temperature of the piping surface of the liquefied gas supply line 3 is detected by the thermometer 5 and transmitted to the heater control unit 4 to control the heating temperature HT of the liquefied gas G by the heater 8, the liquefaction is achieved. As in the case of directly detecting the temperature T of the gas G, reliquefaction of the liquefied gas G can be reliably prevented.

  In the present embodiment, the liquefied gas container 1 is heated by the container heating unit 7, thereby vaporizing the liquid phase part accommodated in the liquefied gas container 1 to cause a phase transition to the gas phase part, thereby liquefied gas. Although an example in which G is sent to the liquefied gas supply line 3 is described, the present invention is not limited to this. The liquefied gas supply apparatus 10 of this embodiment is applicable even when the liquefied gas container 1 is not heated according to the kind of liquefied gas and the pressure in the liquefied gas container 1, for example. That is, for example, it is possible to handle a non-heating type gas using the liquefied gas supply device 10 of the present embodiment. Even in the case of using the heating type liquefied gas G as described above, the liquefied gas container is not always required if the internal pressure P and flow rate of the liquefied gas container 1 are sufficient for the demand (necessary amount). There is no need to heat 1. Therefore, whether or not to heat the liquefied gas container 1 may be appropriately determined according to the type of liquefied gas and the internal pressure P of the liquefied gas container 1.

Examples of the non-heating type gas as described above include NH ₃ , N ₂ O, Cl ₂ , and SF ₆ .

  The liquefied gas supply apparatus and the liquefied gas supply method of the present invention can reliably prevent the liquefied gas from being reliquefied during the supply process without consuming excessive energy for heating the liquefied gas. The present invention is very suitable for use in supplying a large amount of liquefied gas used for manufacturing a semiconductor, a liquid crystal panel, a photovoltaic power generation panel or the like.

DESCRIPTION OF SYMBOLS 10 ... Liquefied gas supply apparatus 1 ... Liquefied gas container 1a ... Outlet 2 ... Container valve 3 ... Liquefied gas supply line 3a ... One end 3b ... Other end 4 ... Heater control part 5 ... Thermometer (temperature detection means)
6 ... Pressure gauge (pressure detection means)
DESCRIPTION OF SYMBOLS 7 ... Container heating part 8 ... Heater 9 ... Pressure reducing valve 9a ... Primary side 9b ... Secondary side C1, C2, C3 ... Communication line G ... Liquefied gas (gas phase)
A ... Current

Claims (6)

A liquefied gas supply device that vaporizes a liquid phase portion accommodated in a liquefied gas container to cause a phase transition to a gas phase portion, and pressurizes the gas phase portion to supply a gaseous liquefied gas to the outside. And
A gas supply line connected at one end to the liquefied gas container and supplying the liquefied gas to the outside;
A pressure reducing valve provided in a path of the gas supply line for reducing the pressure of the liquefied gas;
A heater provided in at least a part of a path between the liquefied gas container and the pressure reducing valve in the gas supply line, and heating the liquefied gas flowing through the gas supply line;
A pressure detector provided in the vicinity of an outlet side of the liquefied gas container in the path of the gas supply line, and detecting an internal pressure of the liquefied gas container;
A temperature detector that is provided in the vicinity of the primary side of the pressure reducing valve in the path of the gas supply line and detects the temperature of at least one of the liquefied gas flowing through the gas supply line or the surface of the gas supply line When,
Based on the internal pressure of the liquefied gas container detected by the pressure detector and the temperature of at least one of the liquefied gas detected by the temperature detector or the surface of the gas supply line, the gas A heater control unit for setting a heating temperature by the heater so as to maintain a temperature of the liquefied gas flowing through the supply line at a temperature higher than a reliquefaction temperature of the liquefied gas under an internal pressure of the liquefied gas container; ,
A liquefied gas supply device comprising:   The heater control unit constantly changes the heating temperature of the heater according to the internal pressure of the liquefied gas container and / or the temperature change of at least one of the surface of the liquefied gas or the gas supply line. The liquefied gas supply device according to claim 1, wherein the heating temperature is set.   3. The liquefaction according to claim 1, wherein the liquefied gas container is heated to vaporize the liquid phase part accommodated in the liquefied gas container to cause a phase transition to the gas phase part. Gas supply device. A liquefied gas supply method for vaporizing a liquid phase portion accommodated in a liquefied gas container to cause a phase transition to a gas phase portion, and for boosting the gas phase portion to supply a gaseous liquefied gas to the outside. And
The liquefied gas in a gaseous state in the liquefied gas container is supplied to the outside by a liquefied gas supply line connected at one end to the liquefied gas container, and the internal pressure of the liquefied gas container and the liquefied gas are supplied. Detecting the temperature of at least one of the liquefied gas in the gas supply line or the surface of the gas supply line;
Heating the liquefied gas flowing through the gas supply line while setting the heating temperature based on the internal pressure of the liquefied gas container and the temperature of the liquefied gas or the surface of the gas supply line By doing so, the temperature of the liquefied gas is maintained at a temperature higher than the reliquefaction temperature of the liquefied gas under the internal pressure of the liquefied gas container.   Depending on the internal pressure of the liquefied gas container and / or the temperature change of at least one of the surface of the liquefied gas or the gas supply line, the heating temperature of the liquefied gas flowing through the gas supply line is constantly set. The liquefied gas supply method according to claim 4, wherein the heating temperature is set while being changed.   6. The liquefaction according to claim 4 or 5, wherein the liquefied gas container is heated to vaporize the liquid phase part accommodated in the liquefied gas container and to cause a phase transition to the gas phase part. Gas supply method.

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