WHAT IS DRS?

1. WHAT IS DRS? Thermoflow, Inc. Thermoflow’s Data Reconciliation System is abbreviated as DRS. The DRS runs from within MS Excel and reconciles a Thermoflow plant model with a set of measured or expected data. • Use the DRS to analyze plant performance test data using a model that follows the laws of physics to ensure closed energy and mass balances. • Use the DRS for on-line plant performance monitoring. Verify key plant measurements such as fuel flow, generator power output, key system pressures, temperatures, and mass flows.

2. Base Case You create the DRS Base Case in any of Thermoflow’s main programs, GT PRO, STEAMPRO, GT MASTER, STEAM MASTER, or THERMOFLEX. The underlying model provides the framework for reconciliation. The measurements or expected data are compared with model outputs. DRS makes reasonable adjustments to model parameters to find the best-fit between measured data and model predictions.

3. New DRS Workbook Thermoflow-DRS menuin Excel gives access to allfunctions. You begin by loading anexisting file created withany of Thermoflow’s coreprograms.

4. Model Inputs Model inputs are used in two ways. Some inputs are treated as given, for example site ambient temperature. This value is fixed from the data. Others are adjusted by DRS to reduce the difference between model output and measured data, for example component efficiencies, fuel flows, or model assumptions. Virtually any core programinput can be set from withinExcel. Inputs are listed in a treestructure that follows themenu structure in the coreprogram.

5. Model Outputs Primary use of model outputs is comparisonwith measured quantities. For example, computed generator power is compared withits measured counterpart as a measure ofhow close the model output is to measureddata set. Unmeasured heat balance pressures, temperatures, and flows whose values are desired at the measured condition are oftenused to “fill-in-the-blanks”, that is round outthe set of data at a measured condition.

6. Main Worksheet Measured data areentered manually in off-line use, or populatedby a bridge program inon-line operation. Each reconciled valuehas its own weightingfactor, filter margin, andaccuracy limit. Sensorhealth reports categorizemeasurement health inbottom-line fashion asLOW, MEDIUM, or HIGH. DRS output is color-codedfor easy interpretation,and all values are availablefor detailed analysis.

7. Calculation DRS runs the calculationengine for the core programfrom Excel. It manages allinput and outputs for youand provides the result backin Excel upon convergence. DRS computes adjustments tomodel input parameters thatminimize the weighted differencebetween measured values andcomputed results. User-specifiedweights bias the result towardsmore reliable measurements,and away from less accurate data.

8. Sensor Health Summary Table Sensor Health Summary table provides overviewof sensor health, followedby detailed breakdown ofeach measurement andhow it differs from themodel. PURPLE entries weredisqualified because theraw measurement wasway off. RED means themeasurement has LOWhealth because it is farfrom the model result. YELLOW indicatesMEDIUM, and GREENindicates HIGH health -measurement and modelagree well.

9. Sensor Health Summary Chart Graphical display bysensor health category. Percentage overviewquickly summarizesstate of plantinstrumentation health.

10. Sensor Health Breakdown Sensor health breakdown shows sensor-by-sensor conditionon a relative basis. Sensor-specific health margins make it easy to tune the DRSso less important measurements can have relatively largeerrors without generating alarms, while more significant valueslike power and fuel flow use tighter limits to ensure problemsare found early.

11. Flexible DRS GUI Like ELINK, the DRS can have a flexible GUIso even user’s who don’t know the modelcan use and benefit from the software. This DRS GUI is used for data input and output. Measurementsgo into the light green boxes, where color-coded reconciledresults are updated just below.