System and method for detecting an abnormal situation associated with a process gain of a control loop
First Claim
1. A method for monitoring operation of a control loop in a process plant, comprising:
- collecting, at one or more of a plurality of computing devices, process gain data associated with a first operating region of a control loop in a process plant, the control loop associated with a unit operation in the process plant, wherein a load variable varies in the first operating region;
determining, at one of the plurality of computing devices, an expected process gain behavior in the first operating region based on the collected process gain data, wherein an expected value of the process gain varies as the load variable varies;
wherein determining the expected process gain behavior in the first operating region comprises fitting a curve to the collected process gain data, and wherein the curve corresponds to the expected process gain behavior in the first operating region;
monitoring, at one of the plurality of computing devices, the process gain during operation of the control loop in the first operating region;
determining, at one of the plurality of computing devices, when the monitored process gain substantially deviates from the curve corresponding to the expected process gain behavior in the first operating region;
determining, at one of the plurality of computing devices, an abnormal situation associated with at least one of the control loop or the unit operation based at least on a substantial deviation from the curve corresponding to the expected process gain behavior in the first operating region; and
generating, at one of the plurality of computing devices, an abnormal situation indicator when an abnormal situation is determined.
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Accused Products
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.
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Citations
31 Claims
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1. A method for monitoring operation of a control loop in a process plant, comprising:
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collecting, at one or more of a plurality of computing devices, process gain data associated with a first operating region of a control loop in a process plant, the control loop associated with a unit operation in the process plant, wherein a load variable varies in the first operating region; determining, at one of the plurality of computing devices, an expected process gain behavior in the first operating region based on the collected process gain data, wherein an expected value of the process gain varies as the load variable varies; wherein determining the expected process gain behavior in the first operating region comprises fitting a curve to the collected process gain data, and wherein the curve corresponds to the expected process gain behavior in the first operating region; monitoring, at one of the plurality of computing devices, the process gain during operation of the control loop in the first operating region; determining, at one of the plurality of computing devices, when the monitored process gain substantially deviates from the curve corresponding to the expected process gain behavior in the first operating region; determining, at one of the plurality of computing devices, an abnormal situation associated with at least one of the control loop or the unit operation based at least on a substantial deviation from the curve corresponding to the expected process gain behavior in the first operating region; and generating, at one of the plurality of computing devices, an abnormal situation indicator when an abnormal situation is determined. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A tangible medium having stored thereon machine executable instructions, the machine executable instructions capable of causing one or more machines to:
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collect process gain data associated with a first operating region of a control loop in a process plant, wherein a load variable varies in the first operating region; determine an expected process gain behavior in the first operating region based on the collected process gain data, wherein an expected value of the process gain varies as the load variable varies; wherein determining the expected process gain behavior in the first operating region comprises fitting a curve to the collected process gain data, and wherein the curve corresponds to the expected process gain behavior in the first operating region; monitor the process gain during operation of the control loop in the first operating region; determine when the monitored process gain substantially deviates from the curve corresponding to the expected process gain behavior in the first operating region; determine an abnormal situation associated with at least one of the control loop or the unit operation based at least on a substantial deviation from the curve corresponding to the expected process gain behavior in the first operating region; and generate an abnormal situation indicator if the abnormal situation is determined.
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18. A method for monitoring operation of a control loop in a process plant, comprising:
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collecting process gain data associated with a first operating region of a control loop in a process plant, wherein a load variable varies in the first operating region; determining an expected process gain behavior in the first operating region based on the collected process gain data associated with the first operating region, wherein an expected value of the process gain varies as the load variable varies; wherein determining the expected process gain behavior in the first operating region comprises fitting a curve to the collected process gain data, and wherein the curve corresponds to the expected process gain behavior in the first operating region; providing data indicative of the curve corresponding to the expected process gain behavior in the first operating region to an expert engine; providing process gain data associated with the control loop during operation of the control loop to the expert engine; utilizing the expert engine to detect an abnormal situation associated with the control loop based on the data indicative of the curve corresponding to the expected process gain behavior in the first operating region and the process gain data associated with the control loop during operation of the control loop; and generating an abnormal situation indicator if the abnormal situation is determined. - View Dependent Claims (19, 20, 21)
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22. A system for monitoring operation of a control loop in a process plant, the system comprising:
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a process gain signature generator configured to generate a signature of expected process gain behavior associated with a control loop in a process plant, wherein the signature is indicative of a gain of a process variable of the control loop versus a load variable of the control loop, and wherein the gain of the process variable versus the load variable is expected to vary as the load variable varies; wherein the process gain signature generator is configured to fit a curve to collected process gain data, and wherein the signature of expected process gain behavior comprises the curve; a process gain evaluator configured to determine if an actual process gain substantially deviates from the curve; and an abnormal situation detector configured to detect an abnormal situation associated with a process unit associated with the control loop based at least in part on whether the actual process gain substantially deviates from the curve and to generate an abnormal situation indicator if the abnormal situation is detected. - View Dependent Claims (23, 24, 25, 26, 27)
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28. A method for facilitating monitoring operation of at least a portion of a process plant, comprising:
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collecting, at one of a plurality of computing devices, process gain data indicative of respective process gains associated with respective unit operations in a process plant, wherein the respective process gains are associated with an operating region, wherein respective load variables vary in the operating region; determining, at one of the plurality of computing devices, expected process gains associated with respective unit operations based on the collected process gain data, wherein expected values of the respective process gains vary as the respective load variables vary; wherein determining the expected process gains associated with respective unit operations comprises fitting respective curves to the collected process gain data, and wherein the respective curves correspond to respective unit operations; providing, at one of the plurality of computing devices, a common set of criteria for determining for each unit operation an abnormal situation associated with the unit operation based at least on whether the process gain associated with the unit operation substantially deviates from the curve associated with the unit operation; permitting, at one of the plurality of computing devices, a user to modify the common set of criteria for a particular unit operation to generate a modified set of criteria; utilizing, at one of the plurality of computing devices, the modified set of criteria to determine for the particular unit operation an abnormal situation associated with the particular unit operation; utilizing, at one of the plurality of computing devices, the common set of criteria to determine for each of at least one other unit operation an abnormal situation associated with the other unit operation; and generating, at one of the plurality of computing devices, an abnormal situation indicator when an abnormal situation for a unit operation is determined. - View Dependent Claims (29)
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30. A method for monitoring operation of a control loop in a process plant, comprising:
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collecting, at one of the plurality of computing devices, process gain data associated with an operating region of a control loop in a process plant, the control loop associated with a unit operation in the process plant, wherein the process gain data is indicative of a gain of a process variable of the control loop versus a load variable of the control loop, and wherein the gain of the process variable versus the load variable varies as the load variable varies; determining, at one of the plurality of computing devices, an expected process gain behavior in the operating region based on the collected process gain data, wherein the process gain is expected to vary as the load variable varies; wherein determining the expected process gain behavior in the operating region comprises fitting a curve to the collected process gain data, and wherein the curve corresponds to the expected process gain behavior in the operating region; monitoring, at one of the plurality of computing devices, the process gain during operation of the control loop in the operating region; determining, at one of the plurality of computing devices, when the monitored process gain substantially deviates from the curve; determining, at one of the plurality of computing devices, an abnormal situation associated with at least one of the control loop or the unit operation based at least on a substantial deviation from the curve; and generating, at one of the plurality of computing devices, an abnormal situation indicator when an abnormal situation is determined.
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31. A method for facilitating monitoring operation of at least a portion of a process plant, comprising:
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collecting, at one of a plurality of computing devices, process gain data indicative of process gains associated with respective unit operations in a process plant, wherein each of the process gains is a gain of a process variable of the respective unit versus a load variable of the respective unit, and wherein each of the process gains varies as the respective load variable varies; determining, at one of the plurality of computing devices, expected process gains associated with respective unit operations based on the collected process gain data, wherein each of the expected process gains varies as the respective load variable varies; and wherein determining the expected process gains associated with respective unit operations comprises fitting respective curves to the collected process gain data, and wherein the respective curves correspond to respective unit operations; providing, at one of the plurality of computing devices, a common set of criteria for determining for each unit operation an abnormal situation associated with the unit operation based at least on whether the process gain associated with the unit operation substantially deviates from the curve associated with the unit operation.
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Specification