Fluid control device, fluid control system, recording medium, and fluid control method

Abstract

The present application provides a fluid control device, a fluid control system, a recording medium and a fluid control method, in order to prevent unnatural behavior of a calculated flow rate output from fluid control, the fluid control device is provided with a fluid control valve and upstream and downstream side pressure sensors on a flow passage, and comprises: an actual flow rate calculation unit that calculates a flow rate based on measured pressures of the upstream and downstream side pressure sensors; and a flow rate output unit that outputs a calculated flow rate calculated by the actual flow rate calculation unit, in the case of judging that the fluid control valve is in a closed state, the flow rate output unit functions to output a zero value regardless of the calculated flow rate, and further comprises a switching unit that switches execution and stop of the zero output function of the flow rate output unit, in the case of the fluid control valve being in an open state and the difference obtained by subtracting the measured pressure on the downstream side from the measured pressure on the upstream side being greater than a prescribed stop threshold value, the switching unit stops the zero output function and causes the flow rate output unit to output the calculated flow rate.

Claims

1. A fluid control device, characterized in that, A fluid control valve, an upstream pressure sensor, and a downstream pressure sensor are installed in the flow channel. The fluid control device includes: The actual flow calculation unit calculates the flow rate based on the measured pressures from the upstream pressure sensor and the downstream pressure sensor. as well as The flow output unit outputs the calculated flow rate derived from the actual flow calculation unit. When the fluid control valve is determined to be in the closed state, the flow output unit performs a zero-value output function, independent of the calculated flow rate. The fluid control device further includes a switching unit that switches between executing and stopping the zero-output function of the flow output unit. When the fluid control valve is open and the difference between the measured pressure from the upstream pressure sensor and the measured pressure from the downstream pressure sensor is greater than a predetermined stop threshold, the switching unit stops the zero output function and causes the flow output unit to output the calculated flow rate.

2. The fluid control device according to claim 1, characterized in that, When the fluid control valve is closed and the absolute difference between the measured pressure of the upstream pressure sensor and the measured pressure of the downstream pressure sensor is less than a predetermined execution threshold, the switching unit executes the zero output function, causing the flow output unit to output a zero value.

3. The fluid control device according to claim 2, characterized in that, The execution threshold is at least greater than the stop threshold.

4. The fluid control device according to claim 1, characterized in that, If either the first or second stopping condition is met, the switching unit stops the zero-output function and causes the flow output unit to output the calculated flow. The first stopping condition is that the fluid control valve is in the open state and the difference between the measured pressure from the upstream pressure sensor and the measured pressure from the downstream pressure sensor is greater than the stopping threshold. The second stopping condition is when the absolute difference between the measured pressure of the upstream pressure sensor and the measured pressure of the downstream pressure sensor is greater than the upper limit of the specified stopping threshold.

5. A fluid control system, characterized in that... ， The fluid control device as described in claim 1 is configured on a portion or all of a plurality of branch channels that are connected to and arranged in parallel with the main channel.

6. A recording medium, characterized in that, The system contains a program for a fluid control device, which is used in the fluid control device. The fluid control device is equipped with a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor on the flow channel. The computer executes the program of the fluid control device, which functions as both an actual flow calculation unit and a flow output unit. The actual flow calculation unit calculates the flow rate based on the measured pressures from the upstream pressure sensor and the downstream pressure sensor. The flow output unit outputs the calculated flow rate calculated by the actual flow calculation unit. When the fluid control valve is determined to be in the closed state, the flow output unit performs a zero-value output function, independent of the calculated flow rate. The computer, by executing the program for the fluid control device, also functions as a switching unit, which switches between executing and stopping the zero-output function of the flow output unit. When the fluid control valve is open and the difference between the measured pressure from the upstream pressure sensor and the measured pressure from the downstream pressure sensor is greater than a predetermined stop threshold, the switching unit stops the zero output function and causes the flow output unit to output the calculated flow rate.

7. A fluid control method, characterized in that, The fluid control method uses a fluid control device. The fluid control device is equipped with a fluid control valve, an upstream pressure sensor, and a downstream pressure sensor on the flow channel. The fluid control method includes: The actual flow rate calculation steps involve calculating the flow rate based on the measured pressures from the upstream and downstream pressure sensors; and The flow output step outputs the calculated flow rate obtained in the actual flow calculation step. In the flow output step, if it is determined that the fluid control valve is in the closed state, a zero value is output regardless of the calculated flow rate. The fluid control method further includes a switching step, which switches the execution and cessation of the zero-value output in the flow output step. In the switching step, if the fluid control valve is open and the difference between the measured pressure from the upstream pressure sensor and the measured pressure from the downstream pressure sensor is greater than a predetermined stop threshold, the calculated flow rate is output in the flow output step.

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