System and method for detecting an abnormal situation associated with a process gain of a control loop

Abstract

In a method for monitoring a control loop in a process plant, process gain data associated with a control loop may be collected. The collected process gain data may be used to determine an expected process gain behavior. For example, expected values of a process variable for given values of a load variable may be determined. As another example, expected changes in a process variable for given changes in a load variable may be determined. Then, during operation of the control loop, the process gain may be monitored. If the monitored process gain substantially deviates from the expected behavior, this may indicate an abnormal situation associated with the control loop.

Description

[0001] References to related applications [0002] This application claims the benefit of US Provisional Patent Application No. 60 / 578,957, filed June 12, 2004, which is incorporated by reference in its entirety into this application for all purposes. Background technique [0003] Process control systems, such as those used in chemical, petroleum, or other processes, typically include one or more centralized or distributed process controllers connected via an analog, digital, or hybrid bus , is communicatively coupled with at least one host or operator workstation and one or more process control and instrumentation devices such as field devices. Field devices, such as valves, valve controllers, switches, transmitters, and sensors (such as temperature sensors, pressure sensors, and flow rate sensors), are placed in the process plant loop environment and perform various functions in the process, such as switching valves, measure process parameters, increase or decrease fluid fl...

AI Technical Summary

Problems solved by technology

Once a problem is identified, maintenance personnel may need to order parts and schedule maintenance procedures, all of which result in a significant amount of time between when the problem occurs and when it is corrected, during which time the processing plant operates at normal and plant speeds. In abnormal conditions associated with non-optimal operation

[0012] Moreover, many processing plants may have experienced abnormal conditions that caused a lot of cost or damage to the processing plant in a relatively short period of time

For example, some abnormal conditions may cause significant damage to equipment, waste of raw materials, or long unplanned shutdowns in processing plants, even if these abnormal conditions only exist for a short time

Thus, detecting a problem in a plant only after it has occurred, no matter how quickly the problem is corrected, can still result in significant waste or disruption in the processing plant.

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