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Process Analysis Using 3D Plots . Dr. Frank Seibert, University of Texas. Presenters. Frank Seibert, University of Texas Terry Blevins, Principal Technologist Julian Post, Paul Muston, Mark Nixon. Introduction.
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Process Analysis Using 3D Plots Dr. Frank Seibert, University of Texas
Presenters • Frank Seibert, University of Texas • Terry Blevins, Principal Technologist • Julian Post, • Paul Muston, • Mark Nixon
Introduction The benefits of 3-D plots in data analysis and history collection of array parameters have been demonstrated in a field trial. In this presentation we addressed: Target applications – Analysis of high speed processes, distributed processes and data from spectral analyzers. Historian modifications/design for support of arrays data. Web enabled 3-D plotting, how array support was used to improve update performance. Field Trial at University of Texas, Pickle Research Center where absorber temperatures were analyzed during startup 3-D plotting and . The technical feasibility of providing 3-D plotting and historian collection of array data has been explore and the value of such a capability proven in two of the target application.
Analysis of High Speed Data Analysis • DeltaV supports measurement and control execution at speed as fast as100 msec. • To enable samples as fast as 100msec to be trended and analyzed, samples may be collected at the controller as an data set/ array and communicated to the historian. • Values are saved in historian and accessed as though they had been reported at the module execution rate. • Module executing at 100msec was created to place high speed data into an array parameter. Arrays communicated at a much slower rate e.g. once per 2 sec. Standard Trend – 100msec Resolution Analysis Tools e.g. Entech Toolkit Profession /Operator Station Application station Historian Array/Data Set Controller
Distributed Process • Temperature and/or pressure distribution across a process unit is often important from an operation perspective. • Univariate plots are ineffective in finding problems • 3-D plots show relationship of measurements and how this relationship changes with time TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT TT
Spectral Analyzers • Spectral analyzers may be used at critical points throughout the process. • Pharmaceutical - inspection of feedstock, blend uniformity, granulation, drying and coating and particle size analysis. Online QA/QC tool for production. • Chemical - acid value, adhesive content, cure, melt index, and polymer processes -reaction monitoring • Refinery, petrochemical - fuel production monitoring • A wide variety of commercial on-line, at-line, and laboratory spectral analyzers are available. • Calibration of an NIR analyzer is based on use of spectral data to developprincipal component analysis(PCA) and projection of latent structures (PLS) models.
Example: NIR Analyzers 3-D Plot of Spectral Data • Careful development of a set of calibration samples and their use in PCA/PLS model development is the basis for near-infrared analytical methods. • For purposes of analysis, the spectral data for a sample should be saved and accessed as one set of data e.g. an array. • 3-D plotting of spectral data can be helpful in screening samples and in analyzing on-line use of spectral data. Off-line PCA/ PLS Model Development Historian Application station On-line Quality Parameter Prediction Array/Data Set NIR Analyzer VIM Interface Controller
Field Trial - DvCH Array Handling Enhancement All samples for an array are held in the database under a single tag, to enable high access speed (minimization of seek times) or logical grouping of data (e.g. spectral analysis) Implementation caters for use of successive elements of array for different measured variables or of the same measured variable (high speed trending) Designed also for use of 2-D array to hold several successive scans of several different measured variables Time Single Variable Time Variable per row entry 2-D array, variable per column
Time tagging in Controller Array time tagging at Controller – high resolution, improving time-stamp accuracy Faster sampling rates possible (scan periods down to 100ms) PHV display of array tag
Field Trial Design Considerations Designed to allow full incorporation in DvCH product Existing facilities to be supported for each individual measured variable in scanned array, as if configured individually for history collection Existing read of tag for specified interval, applied to tag for first element of array, gives all samples for array within time interval in time-stamp order (including array index part) so Samples in time order Samples at same time in array-index order Hence DvCH clients (e.g. PHV, DeltaV Reporter and OPC HDA) can meaningfully access history without code change. (See PHV display on previous slide). Easy to extend client-interface for individual measured variable access etc. e.g. 3-D plotting app
3D Plotting Technology • Various approaches may be taken in visualizing 3D data. Surface Plot, Bar Plot , Series Plot , Line Plot, Scatter Plot, Wirefame Plot, Mesh Plot • Limited number of commercially available components for use with a web browser. • Wire frame plot has may advantages in viewing and analyzing date. 3D Bar Plot 3D Wire Frame and SurfacePlot
3D Plot Capability for Field Trial A 3-D wire frame plot component was selected for the field trial. Used to visualize absorber temperatures collected by the historian as array data. Interface may be accessed using web browser. 3-D plot interface supports rotation and easy access to individual measurement values
Controls Provided for 3D Plot • Selection of Absorber or Stripper • 3D views from different angles • Selection of time span and resolution • Move back in forth in time • Array data used for 3D plots was saved in DeltaV Continuous Historian
3D Views Supported View1 View2 View3
Time Span Selections 1 Hour 15 Minute 4 Hour
SRP CO2 Capture Pilot Plant Gas Capacity, m3/min = 25 Solvent Capacity, liter/min = 130 Inlet CO2 Composition, mol% =1-20 • Capabilities: • - Solvent Screening • - Packing Performance • - Effect of Absorber Inter-cooling • - Solvent Regeneration Variations • - Evaluate Process Dynamics • - Evaluate Heat Exchangers • - Model Validation
Stripping Column Column Diameter, cm = 42.8 Packed Height, cm = 600 Pressure, bar = 0.2-4 Provides for Flashing Feed Windows for Observation Kettle Reboiler Shell and Tube Condenser Plate and Frame Cross Exchanger 11 bar Saturated Steam 10 C Chilled Water
Absorption Column • Column Diameter, cm = 42.8 • Packed Height, cm = 600 • Pressure, bar = 1 • Windows for Observation • Inter-cooling Capability • Extensive Temperature Measurements
MEA Absorber Temperature ProfileL/G = 4.8 (lb/lb), 415 ACFM, 0.3 Lean Loading No Intercooling 86.5% Removal, Run 1 Intercooling (40°C) 93% Removal, Run 2
MEA Absorber Temperature ProfileL/G = 2.1 (lb/lb), 500 ACFM, 0.2 Lean Loading Intercooling (40°C) 82.5% Removal, Run 12 No Intercooling 83.2% Removal, Run 11
Business Results Achieved 3-D plots and historian support of array data is being used to analyze absorber column temperature variation during startup. It is expected that insight gained through the use of 3-D plotting on-line will lead to a reduction in startup time Analysis of high speed data associated with liquid pressure/flow loops is planned and should lead to improvements in the process operations.
Summary 3-D plotting based on historian collection of array data can be used to analyze distributed process and spectral data. Trending of high speed data is possible if data is collected at the controller in an array. The benefits of 3-D plotting of absorber temperature and trending of high speed data will be demonstrated at the UT Pickle Research Center. Field trial work to demonstrate 3-D plotting and historian collection of array data sets a foundation for future enhancement in DeltaV.
Where To Get More Information Graphis 2D and 3D graphing software - Scientific/engineering graph plotting and visualization. http://www.kylebank.com/ Data Visualization – On-line Samples, http://samples.infragistics.com/