Flow rate control device, method of calibrating flow rate of flow rate control device, flow rate measuring device, and method of measuring flow rate using flow rate measuring device

Patent metadata

Field	Value
Publication number	US-10969259-B2
Application number	US-201716309697-A
Country	US
Kind code	B2
Filing date	Jun 22, 2017
Priority date	Jul 5, 2016
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

In a method of calibrating a flow rate control device in which a flow rate is calibrated based on comparison with a flow rate measured by a flow rate reference gauge, a predetermined permissible error range is set for a plurality of flow rate settings, and the permissible error range of at least one specific flow rate setting among the plurality of flow rate settings is set to be smaller than the predetermined permissible error range.

First claim

The invention claimed is:

1. A method of calibrating a flow rate of a flow rate control device, in which the flow rate is calibrated based on comparison with a flow rate measured by a flow rate reference gauge, wherein
a predetermined permissible error range is set for a plurality of flow rate settings, and
a permissible error range of at least one specific flow rate setting among the plurality of flow rate settings is set to be smaller than the predetermined permissible error range,
wherein a calibration of the flow rate control device is performed before the flow rate control device is incorporated into a gas supply system,
the predetermined permissible error range for the plurality of the flow rate settings except for the at least one specific flow rate setting is defined as a continuous target range having a border line extending at constant or linearly expanding with respect to the flow rate, while the permissible error range of the at least one specific flow rate setting is set to have a discrete small target value against the predetermined permissible error range for the plurality of the flow rate settings, and
a calibration for the at least one specific flow rate setting is continued until an error is further reduced than errors in flow rate settings in the vicinity of the at least one specific flow rate setting.

2. A flow rate control device calibrated by the method of calibrating the flow rate according to claim 1 .

3. The flow rate control device according to claim 2 , comprising:
a storage device,
the storage device storing information for identifying the at least one specific flow rate setting.

4. The flow rate control device according to claim 2 , wherein
the flow rate control device is used to measure a volume of a reference volume connected on a downstream side of the flow rate control device.

5. A flow rate measuring device that is connected on the downstream side of the flow rate control device according to claim 4 and for measuring a flow rate of gas flowing into the reference volume, the flow rate measuring device comprising:
a pressure sensor that measures a pressure of the reference volume; and
a temperature sensor that measures a temperature of the reference volume,
wherein the flow rate measuring device is configured to measure the flow rate on the basis of the volume of the reference volume, a rate of pressure change in the reference volume, and the temperature of the reference volume that are measured by passing gas from the flow rate control device to the reference volume at the at least one specific flow rate setting.

6. A flow rate measuring method for use in a gas supply system that includes a flow rate control device, a reference volume provided downstream of the flow rate control device, and a flow rate measuring device that measures a flow rate of gas flowing into the reference volume, the flow rate measuring method comprising the steps of:
calibrating a flow rate of the flow rate control device on the basis of comparison with a flow rate measured by a flow rate reference gauge, in which a predetermined permissible error range is set for a plurality of flow rate settings, and a permissible error range of at least one specific flow rate setting among the plurality of flow rate settings is set to be smaller than the predetermined permissible error range,
wherein a calibration of the flow rate control device is performed before the flow rate control device is incorporated into a gas supply system,
the predetermined permissible error range for the plurality of the flow rate settings except for the at least one specific flow rate setting is defined as a continuous target range having a border line extending at constant or linearly expanding with respect to the flow rate, while the permissible error range of the at least one specific flow rate setting is set to have a discrete small target value against the predetermined permissible error range for the plurality of the flow rate settings, and
a calibration for the at least one specific flow rate setting is continued until an error is further reduced than errors in flow rate settings in the vicinity of the at least one specific flow rate setting;
measuring a volume of the reference volume by passing gas from the flow rate control device to the reference volume at the at least one specific flow rate setting; and
measuring the flow rate with the flow rate measuring device on the basis of a rate of pressure change in the reference volume, a temperature of the reference volume, and the measured volume of the reference volume that are obtained when gas flows into the reference volume.

7. A flow rate measuring method for use in a gas supply system that includes:
a plurality of gas supply lines connected respectively to a plurality of gas supply sources;
a plurality of flow rate control devices provided respectively in the plurality of gas supply lines;
a plurality of first valves provided respectively in the plurality of gas supply lines;
a common gas supply line connected in common to the plurality of gas supply lines on a downstream side of the plurality of first valves;
a second valve provided in the common gas supply line;
a pressure sensor that measures a pressure of a flow passage between the plurality of first valves and the second valve; and
a temperature sensor that measures a temperature of the flow passage between the plurality of first valves and the second valve,
the flow rate measuring method being a method of using the flow passage between the plurality of first valves and the second valve as a reference volume, and measuring a flow rate of gas on the basis of a pressure change indicated by the pressure sensor and the temperature indicated by the temperature sensor when gas flows into the reference volume via any one of the plurality of flow rate control devices while the second valve is closed,
wherein, for at least one flow rate control device among the plurality of flow rate control devices, a flow rate is calibrated based on comparison with a flow rate measured by a flow rate reference gauge, before the flow rate control device is incorporated into the gas supply system, a predetermined permissible error range is set for a plurality of flow rate settings, and a permissible error range of at least one specific flow rate setting among the plurality of flow rate settings is set to be smaller than the predetermined permissible error range, and
after the at least one flow rate control device is incorporated into the gas supply system, a volume of the reference volume is measured by passing gas to the reference volume at the at least one specific flow rate setting, and the measured volume is used to measure the flow rate.

8. A flow rate measuring method for use in a gas supply system that includes:
a plurality of gas supply lines connected respectively to a plurality of gas supply sources;
a plurality of flow rate control devices provided respectively in the plurality of gas supply lines;
a plurality of first valves provided respectively in the plurality of gas supply lines;
a common gas supply line connected in common to the plurality of gas supply lines on a downstream side of the plurality of first valves;
a second valve provided in the common gas supply line;
a pressure sensor that measures a pressure of a flow passage between the plurality of first valves and the second valve; and
a temperature sensor that measures a temperature of the flow passage between the plurality of first valves and the second valve,
the flow rate measuring method being a method of using the flow passage between the plurality of first valves and the second valve as a reference volume, and measuring a flow rate of gas on the basis of a pressure change indicat

Assignees

• Fujikin Kk

Inventors

• Sawada Yohei
• Nagase Masaaki
• Nishino Kouji
• Ikeda Nobukazu

Classifications

• G01F15/005 Primary

  Valves (valves in general F16K) · CPC title

• G01F25/15

  specially adapted for gas meters (G01F25/11 - G01F25/14, G01F25/17 take precedence) · CPC title

• G01F25/13

  using a reference counter · CPC title

• G01F25/10

  of flowmeters · CPC title

• G05D7/00

  Control of flow (level control G05D9/00; control of flow ratio G05D11/00) · CPC title