Calibration data generation apparatus, calibration data generation method, and flow rate control device

A program recording media that stores control program used for a calibration data generation apparatus that generates calibration data for a position sensor that is installed in a fluid control valve for controlling fluid and outputs an output value corresponding to a position of a valve closure member moving in a contacting/separating direction with respect to a valve seat, the calibration data generation apparatus comprising:

• a flow rate sensor that measures a flow rate of the fluid flowing through the fluid control valve;
• a differential pressure control mechanism that controls differential pressure between an upstream side and a downstream side of the fluid control valve;
• a temperature control mechanism that controls temperature of the fluid control valve;
• and a control unit that in a state where the differential pressure control mechanism controls the differential pressure so that the fluid passing through the fluid control valve has sound velocity, uses the temperature control mechanism to change the temperature from a reference temperature to comparative temperature different from the reference temperature, the control program:
• acquiring reference output values at the reference temperature, the reference output values being respectively outputted from the position sensor and the flow rate sensor;
• controlling a valve opening of the fluid control valve, in a state where the temperature control mechanism controls the temperature to the comparative temperature, so that an output value outputted from one of the position sensor and the flow rate sensor becomes equal to the reference output value of the one;
• and
• generating the calibration data on a basis of a calibration data generation output value outputted from the other one of the position sensor and the flow rate sensor.

A calibration data generation method that generates calibration data for a position sensor that is installed in a fluid control valve for controlling fluid and detects a value corresponding to a position of a valve closure member moving in a contacting/separating direction with respect to a valve seat, the calibration data generation method comprising:

• changing temperature of the fluid control valve from a reference temperature to comparative temperature difference from the reference temperature to acquire reference output values at the reference temperature, the reference output values being respectively outputted from the position sensor and a flow rate sensor for measuring a flow rate through the fluid control valve in a state where differential pressure between an upstream side and a downstream side of the fluid control valve is controlled so that the fluid passing through the fluid control valve has sound velocity;
• controlling a valve opening of the fluid control valve so that an output value outputted from one of the position sensor and the flow rate sensor becomes equal to the reference output value of the one in a state where the fluid control valve is kept at the comparative temperature;
• and
• generating the calibration data on a basis of a calibration data generation output value outputted from the other one of the position sensor and the flow rate sensor after the valve opening of the fluid control valve has been controlled.

A flow rate control device comprising:

• a fluid control valve that controls fluid;
• a flow rate sensor that measures a flow rate of the fluid flowing through the fluid control valve;
• a temperature sensor that measures temperature of the fluid control valve;
• and
• a flow rate control unit that performs control so that a flow rate measurement value measured by the flow rate sensor comes close to a predetermined flow rate target value, wherein
• the flow rate control unit comprises:
• a calibration data storage part that stores calibration data indicating a relationship between temperature change of the temperature sensor from a predetermined reference temperature and a deviation of an output value of a position sensor from an output value at the reference temperature, the deviation being caused by the temperature change;
• and
• a valve opening control part that refers to an output value of the temperature sensor to calibrate the output value of the position sensor with the calibration data, and on a basis of the calibrated output value, controls a valve opening of the fluid control valve.