JP5121166B2 - Flow meter and gas flow measurement system - Google Patents

Description

  The present invention relates to a flow meter and a gas flow rate measurement system, and more particularly to a flow meter and a gas flow rate measurement system for measuring a flow rate of gas supplied from a gas supply source filled in a cylinder or the like.

  Conventionally, transactions of gas (gas) filled in an airtight container such as a cylinder or a gas tank (gas holder) (hereinafter sometimes simply referred to as a cylinder or a gas supply source) are determined for each type of gas. It is often done by weight or volume under certain conditions, and is traded exclusively in cylinder units. Similarly, transactions of gas (gas) transported by a tanker truck are often carried out by weight or volume under certain conditions. This gas (gas) is filled in a cylinder or the like on condition that the gas state (gas reference state) at a predetermined pressure (reference pressure) and a predetermined temperature (reference temperature) determined for each gas in a gas filling factory or the like, Be traded.

  By the way, as a method for managing the remaining gas amount of a gas supply source such as a cylinder, there is a method using a liquid level gauge. For example, it is a method that is placed inside a liquefied gas cylinder and the liquid level position is monitored by the sensor unit of the liquid level gauge, and the liquid level of the liquefied gas that gradually decreases while using the gas is below a predetermined position. When this happens, the liquid level gauge outputs that the liquid level is equal to or lower than a predetermined value, so that the gas manager can determine the replacement timing of the liquefied gas cylinder based on the output value.

  By the way, even if the gas filled in a gas supply source such as a cylinder in a gas filling plant or the like is pressurized and flowed in a predetermined process (process) using the gas, the gas such as a cylinder is used in the gas remaining amount management. It will be understood how much gas is used with respect to the weight or volume of the initial gas filled in the supply source. When the amount of gas used is regarded as a weight, for example, there is a method in which the weight of a gas cylinder is constantly measured and a value obtained by removing the measured value from the initial gas cylinder weight is regarded as the gas usage. On the other hand, when the amount of gas used is captured as a volume, there is a method in which an integrated value of the volumetric flow rate measured by a flow meter is obtained and the integrated value is regarded as the amount of gas used.

In addition, when measuring and controlling the gas supply amount when sending gas into the process, a pressure regulator and a flow meter are installed in a gas pipe line disposed between a gas supply source such as a cylinder and a predetermined process. In addition, there is known a flow rate measuring device that measures and controls the volume flow rate by inserting a flow rate controller (see, for example, Patent Document 1).
In general, the volume flow rate is expressed as the flow rate of the gas volume expanded or compressed as the gas state changes. On the other hand, the mass flow rate literally measures the gas flow rate by weight (mass) and is expressed as a flow rate. Gas is a compressible fluid, and mass flow measurement captures the mass (weight) that is not affected by changes in the state of the gas. For this reason, the mass flow measurement can accurately measure the gas flow rate. For example, as shown in FIG. 2, even if the same gas (the same volume (1 m ³ / h)) is filled in the container A and the container B, the pressure in the container A is 2 atm. When the pressure is 1 atm, the measurement instruction value of the volume flow meter is 1 m ³ / h for both the container A and the container B. However measured indicated value of the mass flow meter, the container A is 2m ^{3 /} h, the container B is 1 m ^{3 /} h becomes possible to accurately measure the flow rate. For this reason, it is desirable to use the mass flow rate for the management of the remaining amount of gas. The unit of the flow rate measured by the mass flow meter should originally be indicated by the mass per unit time. However, for convenience, the temperature is 0 ° C. and the pressure is 1 atm (101.3 kPa; the same applies hereinafter). Is specified in terms of volume per unit time.

By the way, in order to manage the remaining amount of gas in the liquefied gas cylinder, the gas flow rate supplied to the predetermined process is constantly measured by inserting a mass flow meter in the gas pipe line arranged between the liquefied gas cylinder and the predetermined process. In addition, a remaining amount management device that integrates the gas usage from the measured gas flow rate and manages the remaining amount of gas based on the accumulated gas usage or the like is known (see, for example, Patent Document 2).
Further, as a device for measuring a mass flow rate, a flow rate measuring device for measuring the mass flow rate by inserting a flow meter in a gas pipe line disposed between a gas supply source and a predetermined process is known (for example, (See Patent Document 3). For example, a flow sensor used as a thermal flow meter is applied to the flow rate measuring device. This flow sensor basically has a pair of temperature measuring elements independently of the heating resistor RH in the fluid flow direction F across the heating resistor RH provided on the silicon base, for example, as shown in FIG. Resistors Ru and Rd are provided to utilize the fact that the degree of diffusion (temperature distribution) of the heat generated from the heating resistor RH varies with the flow of the fluid, The flow rate of the fluid is detected from a change in resistance value due to heat. That is, in the thermal flow meter to which this flow sensor is applied, the heat generated from the heating resistor RH is applied to the temperature-measuring resistor Rd on the downstream side according to the flow rate of the fluid, so that the resistance value changes due to heat. The flow rate is measured by utilizing the fact that it is larger than the temperature sensing resistor Ru on the upstream side.

Incidentally, when a plurality of cylinders (1a, 1b, 1c) are filled with different gases as shown in FIG. 4 and these gases are mixed and supplied to a gas load (not shown), the volume of the mixed gas Volume flowmeters for measuring the volumetric flow rate of the gas flowing through these gas pipelines are provided in the gas pipelines (3a, 3b, 3c) leading from the respective cylinders (1a, 1b, 1c) to the gas load in order to adjust the ratio. (5a, 5b, 5c) is inserted. In this figure, the CO ₂ gas filled in the bomb 1a, the Ar gas filled in the bomb 1b, and the N ₂ gas filled in the bomb 1c are mixed and mixed into a gas load (not shown) as three kinds of gases. The gas is supplied through the gas supply pipe 3.
Japanese Patent No. 2931289 Japanese Patent Laid-Open No. 05-223612 JP 2003-106887 A

  As described above, the trade of the gas (gas) filled in the container is often performed by weight or volume under a certain condition determined for each type of gas. For example, in the case of trading argon gas filled in a cylinder, 10 kg of “gas condition (standard condition of gas)” of “standard temperature of 15 ° C. and standard pressure of 1 atm”, which is a business condition determined by a gas company. It is assumed that one cylinder is filled with argon gas. When gas is supplied to a predetermined process (gas load) using this cylinder as a gas supply source, measurement is performed with a mass flow meter inserted in a gas pipe line disposed between the gas supply source and the predetermined process. As described above, the gas flow rate is displayed as a volume in the standard state of gas (0 ° C., 1 atm) according to commercial practice. However, the gas state in the flow rate measurement unit is the gas reference state (the reference temperature and the reference pressure), which is a transactional condition, and is different from the gas standard state. For this reason, the gas flow rate must be converted into the flow rate at the reference temperature and the reference pressure determined as the reference state of the gas. In other words, when the unit of transaction is performed by volume, that is, when the transaction is performed with the original gas volume filled in the cylinder, the remaining amount of gas in the cylinder is accurately obtained unless the above conversion is performed. I can't.

  In particular, when the reference temperature and the reference pressure of each gas filled in multiple cylinders are different and there is a process (process) that mixes and uses these types of gases, the flow rate inserted in each gas supply path Management that the gas flow rate measured by the meter cannot be grasped unless it is converted to the flow rate of the reference temperature and pressure of each gas, and the remaining amount of gas in each cylinder cannot be grasped. There was a problem above.

For example, as shown in FIG. 4, the CO ₂ gas filled in the cylinder 1a has a reference temperature of 35 ° C., and the Ar gas filled in the cylinder 1b has a reference temperature of 15 ° C. and a reference pressure of 1 atm. The N ₂ gas filled in the cylinder 1c is traded at different reference temperatures and reference pressures such that the reference temperature is 0 ° C. and the reference pressure is 1 atm, and each cylinder (1a, 1b , 1c), it is difficult to grasp the remaining gas amount in each cylinder because the filling cylinder volumes are different, and the remaining amount grasping is extremely complicated.

  In addition, a volumetric flow meter is generally used as a flow meter for measuring the gas supplied from the cylinder. On the other hand, the gas temperature and pressure in the flow measurement unit are the reference temperature and the reference pressure when filling the cylinder. Is different. For this reason, there is a problem that the measured volume flow rate is affected by the temperature and pressure in the flow rate measurement unit, it is difficult to accurately measure the flow rate, and it is difficult to convert the flow rate into the reference state of the gas.

  In addition, assuming the usage environment (temperature, pressure) in the cylinder to a predetermined value in advance, and calculating using the measured values of the temperature and pressure in the flow rate measurement unit, the flow rate in the gas reference state is obtained. However, the usage environment in the cylinder is unknown. For this reason, there has been a problem that the volume flow rate calculated as described above is a value including many errors and is inappropriate as a management value.

For this reason, problems such as the operation of the process being stopped because the gas in the cylinder was emptied earlier than expected, or the cylinder was replaced even though there was still a remaining amount. Have been invited.
The present invention has been made in consideration of such conventional circumstances, and its purpose is to accurately grasp the remaining amount of gas filled in a gas supply source such as a gas cylinder, An object of the present invention is to provide a flow meter capable of optimizing the gas replenishment timing and gas cylinder replacement timing in the cylinder.

  In order to achieve the above-mentioned object, the flow meter according to the present invention is inserted into a gas pipe that guides a gas filled in an airtight container to a predetermined process, and the mass flow rate of the gas flowing through the gas pipe A mass flow rate measuring unit for measuring the gas, and an input unit for inputting gas characteristic information including volume information or mass information and density information of the gas in addition to the reference temperature information and reference pressure information of the gas filled in the container, A standard state volume conversion unit that converts the volume information of the gas into a volume value in a standard state from the gas characteristic information input to the input unit, and a volume at the reference temperature and reference pressure of the gas input to the input unit Integration of the gas from a product of a flow rate conversion unit that converts the mass flow rate into a flow rate, a volume flow rate of the gas converted by the flow rate conversion unit, and a time when the gas is supplied to the predetermined process The remaining amount of gas filled in the container is obtained from the difference between the integrated flow rate calculation unit for obtaining the volume, the volume value of the gas converted by the standard state volume conversion unit, and the integrated flow rate obtained by the integrated flow rate calculation unit. And a remaining amount calculation unit.

In particular, the container includes a characteristic information holding unit that holds gas characteristic information of the gas filled in the container, and the input unit reads the gas characteristic information of the gas held in the characteristic information holding unit. It comprises information reading means.
Further, the characteristic information holding means is a data label printed by encoding the gas characteristic information into a predetermined code.

Next, the flow meter according to the present invention includes a plurality of gas filled in a plurality of hermetically sealed containers, which are inserted into gas pipes that lead to a predetermined process, and each of the gases flowing through the gas pipes. A mass flow rate measuring means for measuring each mass flow rate, and an input means for inputting gas characteristic information including volume information or mass information and density information of each gas in addition to the reference temperature information and reference pressure information of each gas. The standard state volume converting means for converting the volume information of each gas into the volume value in the standard state from the gas characteristic information of each gas inputted from the input means, and the respective gas inputted from the input means A flow rate conversion means for converting the mass flow rate into a volume flow rate at a reference temperature and a reference pressure, a volume flow rate of each gas converted by the flow rate conversion means, and An integrated flow rate calculation means for obtaining an integrated flow rate for each gas from the product of the time when the gas is supplied to the predetermined process, a volume value of each gas converted by the standard state volume conversion unit, and the integrated flow rate, respectively. And a remaining amount calculating means for determining a remaining amount of gas filled in each of the plurality of containers based on a difference from the integrated flow rate for each gas respectively calculated by the calculating unit.

In particular, the plurality of containers are provided with characteristic information holding means for holding gas characteristic information of the respective gases filled in the containers, respectively, and the input means is the gas of each gas held in the data holding means. It is characterized by comprising data reading means for reading characteristic information.
The characteristic information holding means is configured as a plurality of data labels each of which is encoded with a plurality of characteristic information for each of the gases in a predetermined code.

  According to the flow meter of the first aspect of the present invention or the gas flow rate measurement system of the fourth aspect of the present invention, the mass flow rate of the gas flowing through the gas pipeline measured by the mass flow rate measurement unit is determined by the input unit (input means). Since the flow rate conversion unit (flow rate conversion means) uses the input gas characteristic information to obtain the mass flow rate converted to a temperature under a predetermined use condition or a predetermined environmental condition, it is filled at a different reference temperature. The correct mass flow rate for each gas can be obtained. The integrated flow rate of the gas, that is, the use volume of the gas supplied to the gas load can be obtained from the product of the mass flow rate of the gas converted by the flow rate conversion unit and the time when the gas is supplied to the gas load. Furthermore, this flow meter can determine the gas remaining amount in the cylinder from the difference between the volume of the gas filled in the cylinder in the remaining amount calculating unit and the integrated flow rate obtained by the integrated flow rate calculating unit. Therefore, for example, the person in charge of gas management can accurately grasp the remaining amount of gas in the cylinder, and thus can exhibit excellent effects such as being able to optimize the gas replenishment timing for the cylinder.

According to the flow meter according to claim 2 or the gas flow rate measurement system according to claim 5 of the present invention, the characteristic information holding means of the container filled with gas holds the gas characteristic information, and this gas characteristic information Can be obtained quickly and easily and accurate gas characteristic information can be obtained.
Particularly, according to the flow meter according to claim 3 or the gas flow rate measurement system according to claim 6 of the present invention, the characteristic information holding means is a data label in which the characteristic information of the gas is encoded into a bar code or the like. As it is prepared, it is easy to handle.

Hereinafter, a flow meter according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an example of an embodiment for carrying out the present invention, and the present invention is not limited to this figure.
In this figure, reference numeral 1 denotes an airtight container (for example, a cylinder, which is a gas supply source for supplying a gas to a predetermined process (gas load), which is filled with a gas (hereinafter referred to as a gas) for flow rate measurement. ). The cylinder 1 is filled with a gas 2 at a filling factory or the like. The gas 2 filled in the cylinder 1 is supplied to a downstream process (gas load) (not shown) via the gas piping 3.

  On the other hand, a flow meter 10 for measuring the flow rate of the gas flowing through the gas piping 3 is inserted in the gas piping 3. The flow meter 10 includes a mass flow rate measuring unit 11 that measures the mass flow rate of the gas flowing through the gas piping 3, reference temperature information, reference pressure information, volume information, and density information of the gas 2 filled in the cylinder 1. An input unit 12 for inputting gas characteristic information, and a standard state volume conversion for converting the volume information of the gas 2 into the volume value in the standard state from the reference temperature information, reference pressure information and density information of the gas 2 input to the input unit 12 Unit 13, the flow rate conversion unit 14 that converts the mass flow rate of the gas 2 measured by the mass flow rate measurement unit 11 into the volume flow rate at the reference temperature and reference pressure of the gas 2 input from the input unit 12, and the flow rate conversion unit 14 converts The integrated flow rate calculation unit 15 for obtaining the integrated flow rate of the gas 2 from the product of the mass flow rate of the gas 2 and the time when the gas 2 is supplied to the gas load is converted by the standard state volume conversion unit 13. From the difference between the volume information of the gas 2 and the integrated flow rate of the gas 2 obtained by the integrated flow rate calculation unit 15, that is, the difference between the supply amount of the gas 2 supplied to the gas load, the remaining amount of the gas 2 in the cylinder 1 is determined. A remaining amount calculation unit 16 to be obtained and an output unit 17 that outputs the volumetric flow rate of the gas 2 converted by the flow rate conversion unit 14 and the integrated flow rate of the gas 2 calculated by the integrated flow rate calculation unit 15 are configured. Incidentally, for example, the flow sensor of the flow rate measuring device disclosed in Patent Document 1 described above is applied to the mass flow rate measuring unit 11.

  The gas characteristic information is, for example, converted into a predetermined code (for example, a bar code) and posted and attached as a label (characteristic information holding means 18) to the cylinder 1 filled with the gas 2. The code may be read by an input unit 12 that can read the code (for example, a bar code reader (not shown): characteristic information reading means). If the flow meter or the gas flow rate measurement system of the present invention is configured in this way, it is preferable because the remaining gas management of a plant or the like having a plurality of cylinders 1 can be easily performed.

  Schematically, the flow meter of the present invention configured as described above is characterized in that the volume value in the standard state is obtained from the reference temperature information, the reference pressure information, and the density information of the gas 2 by the standard state volume conversion unit 13. The point where the volume information of the gas 2 is converted, the point where the gas flow rate measured by the mass flow rate measuring unit 11 is converted into the volume flow rate at the reference temperature and the reference pressure of the gas 2 by the flow rate converting unit 14, The integrated flow rate calculation unit 15 for obtaining the integrated flow rate of the gas 2 from the product of the flow rate and the time supplied to the gas load is provided, and the volume value of the gas 2 converted by the standard state volume conversion unit 13 in the remaining amount calculation unit 16 The remaining amount of the gas 2 filled in the cylinder 1 is obtained from the difference from the accumulated flow obtained by the accumulated flow calculation unit 15.

Such a characteristic flowmeter will be described in more detail. First, the case where the transaction unit of the gas 2 is the gas mass [kg / s] and the output value of the mass flow measurement unit 11 is the volume [Nm ³ / h] in the standard state of the gas will be described. The input unit 12 acquires mass information and density information of the gas 2 filled in the cylinder 1. Next, the standard state volume conversion unit 13 divides the mass information of the gas 2 filled in the cylinder 1 by the density information and converts it into the volume of the gas 2 in the standard state. When the gas density information is different from the standard state (0 ° C., 1 atm), the standard state volume conversion unit 13 uses the standard temperature information and the reference pressure information of the gas 2 input from the input unit 12 to perform the standard state. Or volume using gas density information provided by the gas supply company.

The flow meter 10 obtains the product of the time t when the gas 2 is supplied to the gas load by using the flow rate thus converted, and the integrated flow rate calculation unit 15 supplies the integrated flow rate, that is, the gas load. Supply amount V [m ³ ] is obtained.
Specifically, the integrated flow rate calculation unit 15
V = ∫Qdt (1)
To calculate the supply amount V [m ³ ]. The remaining amount calculation unit 16 supplies the flow calculated by the integrated flow rate calculation unit 15 from the volume V ₀ [m ³ ] in the standard state of the gas 2 filled in the cylinder 1 obtained by the standard state volume conversion unit 13 described above. The amount of gas V in the cylinder 1 is determined by subtracting the amount V [m ³ ], and the result is output from the output unit 17.

From the cylinder volume thus converted, the integrated flow rate calculation unit 15 performs the above-described calculation to determine the supply amount for the gas load, and the remaining amount calculation unit 16 determines the difference between the cylinder volume and the supply amount. 1 gas remaining amount is led.
Next, the transaction unit of the gas 2 is the volume [L], the measured value of the mass flow measuring unit 11 is the volume [Nm ³ / h] in the standard state of the gas, and the reference temperature of the gas 2 filled in the cylinder 1 is If Tn [° C.], the reference pressure is 1 atm, the gas temperature in the standard state is T [° C.], and the flow rate measured by the mass flow rate measuring unit 11 is Q [Nm ³ / h], then the mass flow rate A value obtained by converting the flow rate Q measured by the measuring unit 11 into the flow rate Qn at the reference temperature can be obtained by the following equation using Boyle-Charles' law.

Q = Qn × {(273 + Tn) / (273 + T)}
= Qn × (273 + Tn) / 273 [Nm ³ / h]
On the other hand, the integrated value V of the amount of gas used at the reference temperature Tn [° C.] can be obtained by the integrated flow rate calculation unit 15 performing the calculation of the above-described equation (1). Therefore, the remaining amount of gas in the cylinder 1 can be obtained by subtracting the accumulated value V of the amount of gas used obtained by the integrated flow rate calculation unit 15 from the gas volume of the cylinder 1 at the time of transaction, by the remaining amount calculation unit 16. The obtained remaining gas amount is output from the output unit 17.

  In addition, what is necessary is just to convert in view of the gas reference | standard condition which is the conditions on transaction, when the measured value of the mass flow measurement part 11 is mass display [kg / s]. Moreover, although embodiment mentioned above demonstrated the case where the residual amount of the gas 2 with which one cylinder 1 was filled was obtained, even if it was filled with the gas 2 of a different kind in each of the several cylinders 1, By using the gas characteristic information, an accurate integrated flow rate can be obtained, and by pulling, the remaining gas amount in the cylinder 1 can be obtained with high accuracy.

  Thus, the flowmeter of the present invention converts the mass flow rate of the gas 2 flowing through the gas pipe 3 measured by the mass flow rate measurement unit 11 into the volume flow rate at the reference temperature and reference pressure of the gas 2 input from the input unit 12. Therefore, it is possible to obtain a correct flow rate for each gas type having a different reference temperature. Further, the flow meter of the present invention further includes an integrated flow rate calculation unit for obtaining an integrated flow rate of the gas 2 from the product of the mass flow rate of the gas 2 converted by the flow rate conversion unit 14 and the time when the gas 2 is supplied to the gas load. 15, the correct integrated flow rate for each gas 2 filled at different reference temperatures, that is, the use capacity of the gas 2 supplied to the gas load can be obtained. Furthermore, the flow meter of the present invention includes a remaining amount calculation unit that obtains the remaining amount of gas in the cylinder 1 from the difference between the capacity of the gas 2 filled in the cylinder 1 and the integrated flow rate calculated by the integrated flow rate calculation unit. Thus, the remaining amount of gas in the cylinder 1 can be accurately grasped, so that the replenishment timing of the gas 2 to the cylinder 1 can be optimized.

  Alternatively, the flow meter of the present invention outputs the mass flow rate of the gas 2 converted by the flow rate conversion unit 14, the integrated usage amount of the gas obtained by the integrated flow rate calculation unit 15 or the remaining amount calculation unit 16, and the remaining gas amount of the cylinder 1. Since the output unit 17 is provided, the output unit 17 confirms the mass flow rate of the gas 2 converted into the temperature under a predetermined use condition or a predetermined environmental condition, the used capacity, and the gas remaining amount of the cylinder 1. It is possible to achieve a great practical effect.

  Further, according to the flow meter or the gas flow rate measurement system of the present invention, the characteristic information holding means 18 is prepared as a data label in which the characteristic information of the gas 2 is encoded in, for example, a barcode or the like, Since the coded gas characteristic information is taken in, the gas characteristic information can be easily taken into the flowmeter 10 without making an input error. For this reason, the flow meter or the gas flow rate measurement system of the present invention is most suitable for the management of the remaining amount of gas in a plant having a large number of cylinders 1 in particular.

  Note that the mass flow rate of the gas 2, the integrated flow rate, and the gas remaining amount in the cylinder 1 are taken in by a device such as a personal computer via a predetermined transmission path (wired transmission path or wireless transmission path), although not particularly shown. It may be configured as follows. By doing in this way, even if it does not confirm with the output part 17 of the flow meter 10 installed in the field the residual amount of the gas 2 in a some cylinder 1, it can confirm with the display apparatus with which a personal computer etc. are equipped. it can.

  Conversely, information such as a reference temperature of the gas 2 filled in the cylinder 1 may be input to the input unit 12 from a personal computer via a wired transmission path or a wireless transmission path. In this case, the property information of the gas 2 can be input from a personal computer or the like without inputting information such as the reference temperature of the gas 2 (property information) from the flow meter 10 installed at the site. There is convenience that setting is completed with little effort.

  Further, in the above-described flow meter or gas flow measurement system of the present invention, the internal pressure of the cylinder 1 is detected when the remaining gas amount or gas mass obtained as described above falls below a predetermined amount, or although not particularly shown. An alarm may be output from the output unit 17 when the pressure value of the pressure sensor to be performed falls below a predetermined value. By configuring in this way, for example, the gas administrator can quickly perform the process of filling the gas 2 in the cylinder 1 when the remaining gas amount, gas mass, or internal pressure in the cylinder 1 decreases.

In addition, depending on the usage of the gas, there is a case where the usage of the gas usage varies greatly during a period of one day or one month. In a certain facility, the usage is changed at a rate of a maximum of 100% with respect to a minimum of 1% of the gas usage during a day. In order to capture such fluctuations in gas usage, a mass flow rate measuring unit with a wide flow rate range is desirable.
However, when it is difficult to secure such a flow rate range, a wide measurement range may be secured by combining a plurality of mass flow rate measuring units having different measurement ranges. Specifically, when the measurement range is supplied to a gas load that fluctuates at a rate of 100% at the maximum with respect to 1% of the minimum amount of gas used, for example, the first measurement range that can be measured is 1 as shown in FIG. % (Preferably, a mass flow rate of 1% or less) to about 50% (low flow rate), the first mass flow measurement unit 11a measuring the second measurable second measurement range is about 40% to 100% (high flow rate) The second mass flow rate measuring unit 11b that measures the above may be inserted in the gas pipe line 3 in series.

In this case, when the mass flow rate of the gas flowing through the gas pipeline 3 exceeds the measurement range of the first mass flow measurement unit 11a, the first mass flow measurement unit 11a outputs the full scale, while the second mass flow measurement unit 11a outputs the full scale. The mass flow rate measuring unit 11b measures and outputs the mass flow rate of the gas flowing through the gas piping 3. Therefore, what is necessary is just to use the measured value of the 2nd mass flow measurement part 11b.
On the other hand, when the gas flow rate is smaller than the second measurement range that can be measured by the second mass flow measurement unit 11b, the measurement value of the second mass flow measurement unit 11b becomes zero, and at this time, the first mass flow measurement unit 11b The measuring unit 11a measures and outputs the mass flow rate of the gas flowing through the gas piping 3. Therefore, what is necessary is just to use the measured value of the 1st mass flow measurement part 11a.

  In addition, the first measurement range in which the flow rate of the gas flowing through the gas pipeline 3 can be measured by the first mass flow measurement unit 11a and the second measurement range in which the second mass flow measurement unit 11b can be measured overlap. In the case of the measurement range, the respective mass flow rate measuring units 11a and 11b output the same mass flow rate. Therefore, the measurement value of either the first mass flow measurement unit 11a or the second mass flow measurement unit 11b may be used.

  The above-described flow meter is a combination of the two mass flow measurement units 11a and 11b, but may be outside the measurement range described above. Also, when combining multiple mass flow measurement units to ensure a wide measurement range, the measurement range of the flow meter can be expanded by configuring the measurement ranges that can be measured by multiple mass flow measurement units. can do. Of course, you may comprise combining two or more mass flow measurement parts.

Incidentally, as a method of the mass flow meter, there are a Coriolis type mass flow meter, a thermal type mass flow meter, and the like, and among these, a mass flow rate measuring unit having a flow rate range corresponding to a change in the amount of gas used is preferable.
The flowmeter of the present invention is not limited to the above-described embodiment, and various changes can of course be made without departing from the scope of the present invention.

It is a block diagram which shows schematic structure of the flowmeter which concerns on one Embodiment of this invention. It is the figure which showed typically the relationship between the molecular state of the gas in the cylinder filled with gas, and the instruction | indication value of a volume flowmeter and a mass flowmeter. It is a figure for demonstrating the basic structure of a thermal type flow rate detection apparatus (flow sensor), and its measurement concept. It is a figure which shows the structural example of the gas supply system which mixes the multiple types of gas each filled with the some cylinder and supplies it to gas load. It is a figure which shows the structural example which expands the measurable flow range by combining the two mass flowmeters from which the measurable measuring range differs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Gas 3 Gas piping 10 Flowmeter 11 Mass flow measurement part 12 Input part 14 Flow rate conversion part 15 Accumulated flow calculation part 16 Remaining quantity calculation part 17 Output part

Claims (6)

Is interposed gas pipe path for guiding the filled airtight containers gas to a predetermined process, and the mass flow rate measurement unit that measures the mass flow rate of flow Ruga scan in the gas distribution line,
An input unit for inputting a gas characteristic information including information of a reference temperature Contact and reference pressure information and the volume value of the gas filled in the container when the gas is filled into the container,
A flow rate conversion unit which translated into a volume flow rate at the reference temperature and reference pressure at which the gas mass flow the mass flow measuring unit is measured into the container is filled,
And accumulated flow rate computation unit for determining the integrated flow rate of the gas flowing from the product of the flow rate conversion unit time gas is supplied from the container with the body volume flow rate converted is to the predetermined process in the gas distribution line,
Flowmeter and a remaining amount calculating unit for obtaining the remaining amount of the filled gas to the container from a difference between the integrated flow the accumulated flow rate computation unit and the volume value of the gas filled in the container is determined. The container is provided with a characteristic information holding means for holding the gas characteristic information,
Wherein the input unit, the flow meter according to claim 1, characterized in that it comprises a characteristic information reading means for reading the gas characteristic information stored in the characteristic information storage unit. 3. The flowmeter according to claim 2, wherein the characteristic information holding means is a data label obtained by encoding the gas characteristic information into a predetermined code and printing it . Interposed respectively a plurality of airtight been Filling been gas in the container into a plurality of gas pipe path for guiding to a predetermined process, a plurality of mass flow to measure the mass flow rate of flow Ru gas meter to the gas distribution line Measuring means;
For each of a plurality of said containers, input means for inputting gas characteristic information including information of a reference temperature Contact and reference pressure information and the volume value of the gas filled in the container when the gas is filled into the container and,
For each of a plurality of said gas distribution line, and a flow rate conversion means for translated into volume flow at the reference temperature and reference pressure at which the gas mass flow the mass flow measuring means has measured the container has been filled,
For each of a plurality of said gas distribution line, integrated flow for obtaining the cumulative flow of the product or Laga scan of the flow rate conversion means time gas is supplied to the predetermined step from the container with the body volume flow rate converted is Computing means;
For each of a plurality of said containers, determined Mel the remaining amount of filled gas in which the accumulated flow rate computation unit and the volume value of the gas is Hama charged to the difference or et previous SL container between the integrated flow rate calculated on the container A gas flow rate measuring system comprising: a remaining amount calculating means. Before SL container, the gas characteristic information includes a characteristic information holding means that holds,
It said input means, a gas flow rate measuring system according to claim 4, characterized in that it comprises a data reading means for reading the Kiga scan characteristic information before held in the characteristic information storage unit. The characteristic information storage means, a gas flow rate measuring system according to claim 5, characterized in that the data labels printed by encoding the characteristic information to the predetermined code.

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