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.

Base Case You create the DRS Base Case in any of Thermoflow’s main programs, GT PRO, STEAM PRO, 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.

New DRS Workbook Thermoflow-DRS menu in Excel gives access to all functions. You begin by loading an existing file created with any of Thermoflow’s core programs.

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 program input can be set from within Excel. Inputs are listed in a tree structure that follows the menu structure in the core program.

Model Outputs Primary use of model outputs is comparison with measured quantities. For example, computed generator power is compared with its measured counterpart as a measure of how close the model output is to measured data set. Unmeasured heat balance pressures, temperatures, and flows whose values are desired at the measured condition are often used to “fill-in-the-blanks”, that is round out the set of data at a measured condition.

Main Worksheet Measured data are entered manually in off -line use, or populated by a bridge program in on-line operation. Each reconciled value has its own weighting factor, filter margin, and accuracy limit. Sensor health reports categorize measurement health in bottom-line fashion as LOW, MEDIUM, or HIGH. DRS output is color-coded for easy interpretation, and all values are available for detailed analysis.

Calculation DRS runs the calculation engine for the core program from Excel. It manages all input and outputs for you and provides the result back in Excel upon convergence. DRS computes adjustments to model input parameters that minimize the weighted difference between measured values and computed results. User-specified weights bias the result towards more reliable measurements, and away from less accurate data.

Sensor Health Summary Table Sensor Health Summary table provides overview of sensor health, followed by detailed breakdown of each measurement and how it differs from the model. PURPLE entries were disqualified because the raw measurement was way off. RED means the measurement has LOW health because it is far from the model result. YELLOW indicates MEDIUM, and GREEN indicates HIGH health - measurement and model agree well.

Sensor Health Summary Chart Graphical display by sensor health category. Percentage overview quickly summarizes state of plant instrumentation health.

Sensor Health Breakdown Sensor health breakdown shows sensor-by-sensor condition on a relative basis. Sensor-specific health margins make it easy to tune the DRS so less important measurements can have relatively large errors without generating alarms, while more significant values like power and fuel flow use tighter limits to ensure problems are found early.

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