Suspicious control valve performance detection

A computing device for detecting a suspect valve in a process plant, the computing device comprising:

• one or more processors;
• and
• a non-transitory computer-readable memory coupled to the one or more processors and storing instructions thereon that, when executed by the one or more processors, cause the computing device to:
• for each of N time periods:
• determine one or more process parameter values for one or more process parameters related to a valve during the time period;
• and
• analyze the one or more process parameter values to determine a plurality of performance metrics for the valve including a change in controller output, a dead band value, and at least one of:
• a change in valve travel or a change in a process variable value;
• and
• determine a status of the valve for the time period by comparing the dead band value to a threshold dead band percentage and comparing at least one of:
• (i) the change in controller output to the change in valve travel or (ii) the product of the change in controller output and a process gain value to the change in the process variable value;
• compare the valve statuses over the N time periods to determine whether the value is operating well for at least a threshold portion of at least a subset of the N time periods;
• in response to determining that the valve is not operating well for at least the threshold portion of at least the subset of the N time periods, determine that the valve is a suspect valve;
• and
• provide an indication of the suspect valve to a user interface for display to a user.

A process control system comprising:

• a controller configured to control a valve;
• the valve configured to control operation of a process plant entity executing within a process plant;
• and
• a computing device including:
• one or more processors;
• and
• a non-transitory computer-readable memory coupled to the one or more processors and storing instructions thereon that, when executed by the one or more processors, cause the computing device to:
• for each of N time periods:
• determine one or more process parameter values for one or more process parameters related to the valve during the time period;
• and
• analyze the one or more process parameter values to determine a plurality of performance metrics for the valve including a change in controller output, a dead band value, and at least one of:
• a change in valve travel or a change in a process variable value;
• and
• determine a status of the valve for the time period by comparing the dead band value to a threshold dead band percentage and comparing at least one of:
• (i) the change in controller output to the change in valve travel or (ii) the product of the change in controller output and a process gain value to the change in the process variable value;
• compare the valve statuses over the N time periods to determine whether the value is operating well for at least a threshold portion of at least a subset of the N time periods;
• in response to determining that the valve is not operating well for at least the threshold portion of at least the subset of the N time periods, determine that the valve is a suspect valve;
• and
• provide an indication of the suspect valve to a user interface for display to a user.

A method for reducing a false alarm rate in suspect valve detection using a moving time window, the method comprising:

• determining, by one or more processors, a status of a valve in a process plant for each of N time periods by determining a plurality of performance metrics for the valve including a change in controller output, a dead band value, and at least one of:
• a change in valve travel or a change in a process variable value, comparing the dead band value to a threshold dead band percentage and comparing at least one of:
• (i) the change in controller output to the change in valve travel or (ii) the product of the change in controller output and a process gain value to the change in the process variable value;
• determining, by the one or more processors, a proportion of at least a subset of the N time periods in which the valve status indicates the valve is operating well;
• and
• providing, by the one or more processors, an indication that the valve is a suspect valve to a user interface for display to a user in response to determining that the proportion is less than a threshold proportion.

A method for detecting a suspect valve in a process plant, the method comprising:

• determining, by one or more processors, one or more dynamic process parameter values for one or more dynamic process parameters related to a valve, the one or more dynamic process parameters including a dynamic controller output which is a controller output multiplied by a process gain divided by a combination of a time constant and a dead time;
• analyzing, by the one or more processors, the one or more dynamic process parameter values including the dynamic controller output to determine a status of the valve;
• and
• providing, by the one or more processors, an indication that the valve is a suspect valve in accordance with the status of the valve to a user interface for display to a user.