Abstract
Process Data Reconciliation (PDR) is a certified method that calculates the most likely values considering process measurement uncertainties and continuously closing all energy-, mass- and material balances. All interdependencies between measurements within the entire plant process are mapped in a covariance matrix. There are several areas where monetary and non-monetary benefits for the plant operator are generated: 1. Safety 2. Transparency 3. Financial benefits Transparency The "true" state of the process is becoming visible. The traditional belief in absolute measurement values is changed into a realistic view on values that are addressed with uncertainties. With this, new insights are won in process areas, which are not or insufficiently instrumented. Process data reconciliation deduces missing process data by regarding the entire process, all its redundancies and their relationship to each other. This creates a detailed understanding for the processes and interactions within the processes. Safety The methodology of process data reconciliation represents the latest development level. It is the most precise tool for process control & analysis and is used world-wide. VALI and ProcessPlus^<TM> are certified according to VDI2048 and tested by several national institutions. The more transparent process data becomes to the operator, the safer he can control the plant. Online process data reconciliation enables the view on true process data and gives instant indications to sub-optimal process behaviour as well as malfunctioning components and leakages. Furthermore, the ability to instantly differentiate between a process change and a drifting measurement is crucial to the safe operation of nuclear power plants. Financial benefits Financial benefits are created by several aspects: Plant efficiency is increased by the rise in process transparency. Suboptimal conditions in the plant are rapidly located. Minimizing uncertainty of measurement values makes it safer to approximate limit values more closely thus enabling the operator to maximize the output. Furthermore, there is a substantial reduction in maintenance cost enabled through process transparency. The shift from preventive to conditionbased maintenance can be safely executed. In addition, contracts with suppliers concerning retrofit measures need to be based on the VDI 2048 guideline to forgo customer penalizing. Highly accurate and low-cost acceptance tests with process data reconciliation are performed using operational data only and ensure an independent view on the conducted measures. Process data reconciliation is per Gauss' definition the best possible tool to describe the true state of a plant's process. Highly precise measurements can only contribute to sharpening the total view, but never exceed the overall precision of data reconciliation.
