Fluid control device, fluid control system, storage medium storing a program for fluid control device, and fluid control method

Patent metadata

Field	Value
Publication number	US-2022413521-A1
Application number	US-202217847822-A
Country	US
Kind code	A1
Filing date	Jun 23, 2022
Priority date	Jun 25, 2021
Publication date	Dec 29, 2022
Grant date	—

Abstract

In order to prevent unnatural behavior of a calculated flow rate, provided is a fluid control device in which a fluid control valve and upstream and downstream pressure sensors are provided on a flow path. The device includes a calculation unit configured to calculate a flow rate based on measured pressures; and an output unit configured to output the calculated flow rate, and exhibit a zero output function of outputting a zero value regardless of the calculated flow rate when the valve is in a closed state. The device is further configured to switch between execution and stop of the zero output function, and when the valve is in an open state and a difference between the measured pressures of the pressure sensors is larger than a threshold, stop the zero output function and cause the flow rate output unit to output the calculated flow rate.

First claim

What is claimed is:

1 . A fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the device comprising:
an actual flow rate calculation unit configured to calculate a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure sensor; and a flow rate output unit configured to output a calculated flow rate calculated by the actual flow rate calculation unit, wherein the flow rate output unit is configured to exhibit a zero output function that is a function of outputting a zero value regardless of the calculated flow rate when it is determined that the fluid control valve is in a closed state, the device further comprises a switching unit configured to switch between execution and stop of the zero output function by the flow rate output unit, and when the fluid control valve is in an open state and a difference obtained by subtracting the measured pressure of the downstream pressure sensor from the measured pressure of the upstream pressure sensor is larger than a predetermined stop threshold, the switching unit stops the zero output function and causes the flow rate output unit to output the calculated flow rate.

2 . The fluid control device according to claim 1 , wherein when the fluid control valve is in the closed state and an absolute difference between the measured pressure of the upstream pressure sensor and the measured pressure of the downstream pressure sensor is smaller than a predetermined execution threshold, the switching unit executes the zero output function and causes the flow rate output unit to output the zero value.

3 . The fluid control device according to claim 2 , wherein the execution threshold is larger than at least the stop threshold.

4 . The fluid control device according to claim 1 , wherein the switching unit stops the zero output function and causes the flow rate output unit to output the calculated flow rate when either the following first stop condition or second stop condition is satisfied:
(first stop condition) when the fluid control valve is in the open state and the difference obtained by subtracting the measured pressure of the downstream pressure sensor from the measured pressure of the upstream pressure sensor is larger than the stop threshold, (second stop condition) when an absolute difference between the measured pressure of the upstream pressure sensor and the measured pressure of the downstream pressure sensor is larger than a predetermined upper limit value larger than the stop threshold.

5 . A fluid control system comprising the fluid control device according to claim 1 disposed in a part or all of a plurality of branch flow paths coupled to a main flow path and provided in parallel.

6 . A storage medium storing a program for a fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the program causing a computer to function as:
an actual flow rate calculation unit configured to calculate a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure sensor; and a flow rate output unit configured to output a calculated flow rate calculated by the actual flow rate calculation unit, wherein in a configuration in which, when it is determined that the fluid control valve is in a closed state, the flow rate output unit exhibits a zero output function that is a function of outputting a zero value regardless of the calculated flow rate, the program further causes the computer to function as a switching unit configured to switch execution and stop of the zero output function by the flow rate output unit, and the switching unit stops the zero output function and causes the flow rate output unit to output the calculated flow rate when the fluid control valve is in an open state and a difference obtained by subtracting the measured pressure of the downstream pressure sensor from the measured pressure of the upstream pressure sensor is larger than a predetermined stop threshold.

7 . A fluid control method using a fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the method comprising the steps of:
calculating a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure sensor; and outputting a calculated flow rate calculated by the actual flow rate calculation unit, wherein in a method in which, in the outputting the calculated flow rate, when it is determined that the fluid control valve is in a closed state, a zero value is output regardless of the calculated flow rate, the method further comprises switching between execution and stop of the output of the zero value by the outputting the calculated flow rate, and when the fluid control valve is in an open state and a difference obtained by subtracting the measured pressure of the downstream pressure sensor from the measured pressure of the upstream pressure sensor is larger than a predetermined stop threshold in the switching, the calculated flow rate is output in the outputting the calculated flow rate.

8 . A fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the device comprising:
an actual flow rate calculation unit configured to calculate a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure sensor; and a flow rate output unit configured to output a calculated flow rate calculated by the actual flow rate calculation unit, wherein the flow rate output unit exerts a negative burst cutting function that is a function of outputting a zero value regardless of the calculated flow rate when the fluid control valve is in an open state and the flow rate calculated by the actual flow rate calculation unit is a negative flow rate.

9 . The fluid control device according to claim 8 , wherein the negative burst cutting function stops when an elapsed time after the fluid control valve is opened exceeds a predetermined set time.

10 . The fluid control device according to claim 9 , wherein the set time is changeable.

11 . The fluid control device according to claim 8 , wherein whether to cause the flow rate output unit to exhibit the negative burst cutting function is selectable.

12 . A storage medium storing a program for a fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the program causing a computer to function as:
an actual flow rate calculation unit configured to calculate a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure sensor; and a flow rate output unit configured to output a calculated flow rate calculated by the actual flow rate calculation unit, wherein the flow rate output unit exerts a negative burst cutting function that is a function of outputting a zero value regardless of the calculated flow rate when the fluid control valve is in an open state and the flow rate calculated by the actual flow rate calculation unit is a negative flow rate.

13 . A fluid control method using a fluid control device in which a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are provided on a flow path, the method comprising the steps of:
calculating a flow rate based on measured pressures of the upstream pressure sensor and the downstream pressure se

Assignees

• Horiba Stec Co Ltd

Inventors

• Matsumoto Sota
• Nagai Kentaro
• Hisamori Yosuke
• Matsuura Kazuhiro

Classifications

• G05D7/0623 Primary

  characterised by the set value given to the control element · CPC title

• G01F1/363 Primary

  with electrical or electro-mechanical indication (G01F1/37 and G01F1/38 take precedence) · CPC title

• G05D7/0635 Primary

  by action on throttling means (G05D7/0688, G05D7/0694 take precedence) · CPC title

• G05D16/20

  characterised by the use of electric means · CPC title

• G05D16/028

  Controlling a pressure difference (control of flow G05D7/00) · CPC title