| 主权项 |
1. A method for operating a flow-control valve within a fluid system, comprising:
computing a plurality of original iso-curves in non-transitory computer media associated with an electronic controller, each of the plurality of original iso-curves containing information correlating a valve position with a flow through the flow-control valve; translating an external control signal provided to the electronic controller to a desired flow rate based on one of the plurality of original iso-curves, the external control signal being indicative of a parameter setpoint other than a desired flow rate setpoint, and selecting one of the plurality of original iso-curves as an original iso-curve; automatically establishing a flow rate set point based the desired flow rate, the flow rate set point being sufficient to satisfy the parameter setpoint; providing a command signal to the flow-control valve to effect a change in position of the flow-control valve to achieve the flow rate setpoint independently of changes in pressure across the flow-control valve; monitoring the flow through the flow control valve and the external control signal for changes; adjusting the command signal, in real time, as necessary, based on the original iso-curve, to preserve the flow through the control valve; re-calibrating the original iso-curve at periodic intervals by replacing the original iso-curve with an updated iso-curve belonging to the plurality of original iso-curves, the re-calibration being carried out when a then-present actual flow through the flow-control valve falls outside of a predetermined threshold relative to the desired flow indicating a disturbance in the process; wherein the re-calibration is performed by the electronic controller based on a valve flow coefficient and other constants, which are determined in the electronic controller based at least in part on a valve flow signal indicative of the then-present actual flow through the flow-control valve that is received by the electronic controller. |
