Flow measurement and control with bubble detection

A method of controlling the flow rate of a liquid through a flow conduit coupled to a controllable valve and a liquid flow sensor, liquid flow sensor including a sensor conduit and the liquid including a plurality of bubbles formed therein, the method comprising acts of

• repeatedly sensing a flow signal indicative of the flow rate of the liquid flowing in the sensor conduit;
• determining, based upon at least one parameter of the flow signal, whether at least one bubble is disposed in the liquid within the sensor conduit;
• providing, in response to a determination that no bubble is disposed in the liquid within the sensor conduit, control parameters for the controllable valve based upon the most recently sensed flow signal;
• providing, in response to a determination that the at least one bubble is disposed in the liquid within the sensor conduit, control parameters for the controllable valve based upon other than the most recently sensed flow signal;
• controlling the controllable valve according to the control parameters;
• waiting a predetermined period of time in response to a determination that the at least one bubble is disposed in the liquid within the sensor conduit;
• determining, after the predetermined period of time whether the at least one bubble is still disposed in the liquid within the sensor conduit based upon the at least one parameter of the flow signal;
• and
• executing, in response to a determination that the at least one bubble is still disposed in the liquid within the sensor conduit, a controlled force procedure to remove the at least one bubble from the liquid within the sensor conduit.

A system for measuring a flow rate of a liquid flowing in a flow conduit, the liquid including a plurality of bubbles formed therein, the system comprising:

• a liquid flow sensor including a sensor conduit fluidly coupled to the flow conduit, the liquid flow sensor being configured to sense a flow rate of the liquid flowing in the sensor conduit and provide a flow signal indicative of the flow rate of the liquid flowing in the sensor conduit;
• a bubble detection module, coupled to the liquid flow sensor, to receive the flow signal and determine, based upon at least one parameter of the flow signal, whether at least one bubble is disposed in the liquid within the sensor conduit, the bubble detection module being configured to:
• provide, in response to a determination that no bubble is disposed in the liquid within the sensor conduit, a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon a most recently sensed flow signal, and provide, in response to a determination that the at least one bubble is disposed in the liquid within the sensor conduit, at least one of:
• a) a flow rate signal based upon the most recently sensed flow signal and an alert signal indicative of a presence of the at least one bubble, and
• b) a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon other than the most recently sensed flow signal, wherein the flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon other than the most recently sensed flow signal comprises a previously sensed flow rate signal for which it was previously determined that no bubble was disposed in the liquid within the sensor conduit.

A method of measuring a flow rate of a liquid flowing in a liquid flow sensor, the liquid flow sensor including a sensor conduit and the liquid including a plurality of bubbles formed therein, the method comprising acts of:

• repeatedly sensing a flow signal indicative of the flow rate of the liquid flowing in the sensor conduit;
• calculating, responsive to the act of repeatedly sensing, a running average of a value of the at least one parameter of the flow signal;
• determining, based upon at least one parameter of the flow signal, whether at least one bubble is disposed in the liquid within the sensor conduit, wherein the act of determining includes an act of determining whether a most recently sensed value of the at least one parameter of the flow signal deviates from the running average by more than a threshold value;
• providing, in response to a determination that no bubble is disposed in the liquid within the sensor conduit, a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon a most recently sensed flow signal;
• and
• providing, in response to a determination that the at least one bubble is disposed in the liquid within the sensor conduit, at least one of:
• a) a flow rate signal based upon the most recently sensed flow signal and an alert signal indicative of a presence of the at least one bubble, and
• b) a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon other than the most recently sensed flow signal.

A system for measuring a flow rate of a liquid flowing in a flow conduit, the liquid including a plurality of bubbles formed therein, the system comprising:

• a liquid flow sensor including a sensor conduit fluidly coupled to the flow conduit, the liquid flow sensor being configured to sense a flow rate of the liquid flowing in the sensor conduit and provide a flow signal indicative of the flow rate of the liquid flowing in the sensor conduit;
• a bubble detection module, coupled to the liquid flow sensor, to receive the flow signal and determine, based upon at least one parameter of the flow signal, whether at least one bubble is disposed in the liquid within the sensor conduit, the bubble detection module being configured to:
• provide, in response to a determination that no bubble is disposed in the liquid within the sensor conduit, a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon a most recently sensed flow signal, and provide, in response to a determination that the at least one bubble is disposed in the liquid within the sensor conduit, at least one of:
• a) a flow rate signal based upon the most recently sensed flow signal and an alert signal indicative of a presence of the at least one bubble, and
• b) a flow rate signal indicative of the flow rate of the liquid flowing in the liquid flow sensor based upon other than the most recently sensed flow signal,
• a controllable valve in fluid communication with the flow conduit, to control the flow rate of the fluid flowing in the flow conduit based upon control parameters provided to the controllable valve;
• and
• a controller, coupled to the bubble detection module, to receive the flow rate signal and the alert signal and provide the control parameters to the controllable valve.