Category Archive: Metrics

Jan
14

Evaluating Control System Performance

Process Control System

The operation of industrial process control systems often involves the control of multiple unit operations with hundreds of measurements and control loops, as illustrated below. Although these systems are designed to automatically archive operational data in an historian, it is time consuming to examine historical data to determine if there has been a change in …

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Dec
10

Foundation Book Promotional Kit

Foundaton Book Display

The single loop and multi-loop control techniques most often used in automating continuous and batch processes are addressed in the book Control Loop Foundation – Batch and Continuous Processes. Similarly, the advanced control techniques that are most often utilized in the process industry are addressed in the book Advanced Control Foundation – Tools, Techniques, and …

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Nov
19

Application of Online Data Analytics to a Continuous Process

Application of Online Data Analytics to a Continuous Process Polybutene Unit

DeltaV Online Batch Data Analytics will be introduced next year in DeltaV v12. We worked closely with Lubrizol to demonstrate a prototype of this product in a field trails at the Rouen, France facility. Lubrizol and Emerson collaborated on a number of Emerson Exchange workshops that addressed different aspects of batch data analytics and the …

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Oct
22

Continuous Data Analytics – Impact of Transport Delay

Continuous Digester

When developing a PLS models for quality parameter prediction, the deviation of measurement values from their mean must be shifted in time to account for the time required for a change in the input to impact the quality parameter. Similarly, these delays should be taken into account in the processing of the deviation values used …

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Oct
15

Continuous Data Analytics – Impact of Grade Change

Continuous Reactor Example

The process operating points of a continuous process can shift with changes in the product grade that is manufactured. One example of this is a continuous reactor in which the target for output composition changes with product grades. To change the output composition, it is often necessary to change the operating point of one or …

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Oct
08

Continuous Data Analytics – Quality Parameter Prediction

Swing Boiler Example

The prediction of quality parameters using Partial Least Squares (PLS) models is often the preferred technique when dealing with collinear data where multiple process input changes impact similar process output measurements. Predictions based on this linear technique can be used to extrapolate outside the data range used in model development. Process interactions may be accounted …

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Sep
24

Continuous Data Analytics

ContinuousDataAnalyticsFieldtrailProcess_Rev

One of the areas addressed by the DeltaV future architecture team over the last two years has been the research and development of on-line continuous data analytics for fault detection quality parameter prediction. This year a prototype of this capability is being tested at two plants in Texas and one plant in Canada. Lubrizol, Deer …

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Jul
30

Boot Camp for New Employees

BookOutline

Courses required for an engineering degree are designed to provide the student with a sound technical foundation for work in industry. However, in most cases these courses do not address the terminology and common practices that an engineer must know to design, implement, checkout and commission a process control system. Universities can help bridge this …

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Jan
30

Centrifugal Compressor Efficiency – Part 4

CompleteEff

Part 1 of the centrifugal compressor efficiency series addressed the measurements and parameters that must be calculated to determine compressor efficiency. In Part 2-3 of this series we examined one way of calculating the enthalpy and entropy of the gas stream at the compressor suction and discharge and isentropic enthalpy for the refrigerant R134a. Once …

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Jan
23

Centrifugal Compressor Efficiency – Part 3

Entropy R134a

Part 1 of the centrifugal compressor efficiency series addressed the measurements and parameters that are used to calculate compressor efficiency. In Part 2 of this series we examine how these measurements are used to calculate the enthalpy of the gas stream at the compressor suction and discharged for the refrigerant R134a. This calculation utilized bilinear …

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