Abstract
Operational decisions related to plant performance monitoring mainly result from raw process measurement analysis. When first signs of sub-optimal behavior occur, traditional methods mainly focus on the observation of selective pieces of information. The main disadvantages of these methods are: ・Investigation efforts are required to localize the problems, entailing time losses and costs; ・Validity and reliability of the pieces of information cannot be checked as long as the measurements are observed individually. The problem is not the lack of methods and techniques but rather a lack of reliable and consistent data and information across the entire plant. To overcome drawbacks of traditional methods, measurements are considered as interacting with one another. When related to the other measurements of the plant, the observed information becomes of an interest: its incoherency to the others identifies and localizes a problem. The Data Validation and Reconciliation technology (DVR) is based on an advanced process data coherency treatment. By using all available plant information and by closing the plant heat and mass balances based on rigorous thermodynamics, the method generates: ・A single set of reliable and most accurate plant process data; ・Alarms for incoherent measurements, highlighting potential problems; ・Alarms for equipment and process performance degradation; ・Alarms for faulty and drifting measurements. The use of the advanced DVR software package VALI offers various benefits as it allows to base operational decisions on reliable and accurate data.
