Estimating A Maximum Flow Through A Heat Exchanger

A valve comprising:

• a valve body defining a fluid path from an inlet port and an outlet port;
• a valve member situated in the fluid path, the valve member selectively movable between a closed position blocking the fluid path and an open position;
• an actuator secured relative to the valve body for selectively moving the valve member between the closed position and the open position;
• a controller having a memory storing a lower threshold and an upper threshold and in operative communication with the memory, the actuator, and a flow sensor;
• the controller programmed to iteratively:
• read a time series of signals from the flow sensor;
• produce a time series of flow rates from the time series of signals;
• produce an averaged series of values by determining a plurality of moving averages of the time series of flow rates;
• produce a first bounded series of values by replacing values of the averaged series that are below the lower threshold with values that equal the lower threshold;
• produce a second bounded series of values by replacing values of the first bounded series that exceed the upper threshold with values that equal the upper threshold;
• produce a maximum flow rate by applying a maximum filter to the second bounded series, the maximum filter returning the largest value of the second bounded series;
• read a set point signal indicative of a flow rate through the valve;
• limit the set point signal to the produced maximum flow rate;
• produce an actuation signal from the limited set point signal;
• and
• transmit the actuation signal to the actuator, the actuation signal indicating a position of the valve member.

A computer program comprising instructions which, when executed by a local controller, cause the local controller to iteratively:

• read a time series of signals from a flow sensor;
• produce a time series of flow rates from the time series of signals;
• transmit the time series of flow rates to a remote controller using a digital communication protocol;
• receive a maximum flow rate from the remote controller using the digital communication protocol;
• read a set point signal;
• limit the set point signal to the received maximum flow rate;
• produce an actuation signal from the limited set point signal;
• and
• transmit the actuation signal to an actuator, the actuation signal indicating a position of a valve member.

A computer program comprising instructions which, when executed by a remote controller, cause the remote controller to iteratively:

• receive a time series of flow rates from a local controller using a digital communication protocol;
• produce an averaged series of values by determining a plurality of moving averages of the time series of flow rates;
• produce a first bounded series of values by replacing values of the averaged series that are below a lower threshold with values that equal the lower threshold;
• produce a second bounded series of values by replacing values of the first bounded series that exceed an upper threshold with values that equal the upper threshold;
• produce a maximum flow rate by applying a maximum filter to the second bounded series, the maximum filter returning the largest value of the second bounded series;
• and
• transmit the maximum flow rate to the local controller using the digital communication protocol.