LIQUID SUPPLY SYSTEM AND METHOD FOR CONTROLLING LIQUID SUPPLY SYSTEM

摘要

A liquid supply system includes a pump having a fluctuating member separating pump and working chambers thereof, a supply and discharge section which supplies a working gas to the working chamber and discharges the working gas from the working chamber, a suction valve, a discharge valve, a pressure sensor for detecting the pressure within a space including the working chamber, a flow rate sensor for detecting the flow rate of the working gas, and a control section. The control section closes the discharge valve and opens the suction valve, calculates a change in the volume of the working chamber from the detected flow rate, controls the supply and discharge section such that the volume change becomes zero, and uses, as an estimated suction-side hydraulic head pressure of the liquid, the pressure detected in a state in which the volume change has becomes zero.

主权项

1. A liquid supply system comprising:
a pump which includes a pump chamber into which a liquid supplied from a liquid container flows and from which the liquid flows out, a working chamber into which a working gas is supplied and from which the working gas is discharged, and a fluctuating member which separates the pump chamber and the working chamber from each other, the pump being configured to suck and discharge the liquid in accordance with change in a volume of the pump chamber caused by fluctuation of the fluctuating member; a supply and discharge section configured to supply the working gas to the working chamber and discharge the working gas from the working chamber; a suction valve configured to open and close an inflow passage through which the liquid flows into the pump chamber; a discharge valve configured to open and close a discharge passage through which the liquid flows out of the pump chamber; a pressure sensor configured to detect pressure within a space including the working chamber; a flow rate sensor configured to detect flow rate of the working gas which flows into and flows out of the working chamber; and a control section configured to control the supply and discharge section, the suction valve, and the discharge valve, wherein the control section is configured to close a first valve which is one of the suction valve and the discharge valve and open a second valve which is the other of the suction valve and the discharge valve, calculate a change in a volume of the working chamber on the basis of the flow rate detected by the flow rate sensor, control the supply and discharge section such that the change in the volume becomes zero, and use, as an estimated hydraulic head pressure of the liquid on the second valve side, the pressure detected by the pressure sensor in a state in which the change in the volume has become zero.