Process object: Design Info tab

General Info frame

These properties appear in the General Info frame on the Design Info tab.

• Out of Service: A balance point object such as a process, node or tank has a status attribute which indicates whether it is in service (IS) or out of service (OS). By default all balance point objects are IS. If the Out of Service checkbox is checked, the balance point will be treated as if there are no flowing streams connected to it, even if there are connected streams that appear to have some measured flow. Details will be explained in the description of the Out of Service checkbox on the Results tab. If you want to apply this setting to existing event data, click the command button next to this checkbox.

• OS when No Flowing: This option in is used when there is no flow meter, but it can be decided whether it is flowing or not by control valve or logic. Even though the object has no flow meter (unmeasured stream), if the flow rate is estimated to zero from control valve opening and the virtual tag, it is internally set as out of service.

• Normal/Boiler & Heater: Normal means that the process/node is a normal balance point object. If you set the process/node to Boiler & Heater, the object can calculate thermal efficiency with enthalpy change of input gas and flue gas.

• Block Operation Mode: You can choose the mode for block operation. For more information, see Block Op. Mode.

• Process Unit: Sets the process unit.

• Comment: This text box is for editing any comment related to general design information.

Mass and Volume tabs

These tabs contain, for either mass or volume respectively, minimum and maximum feed rates, and a default feed rate and a tolerance for the process balance point.

The feed rates are only for reference purposes. The algorithm ignores them, but users may wish to refer to these values when evaluating the results of reconciliation.

The tolerance is used by the algorithm, but only when the Forced Balance checkbox on the DR Solver tab of the Options dialog box is selected. Since the default value of this Forced Balance checkbox is unchecked, the tolerance is normally ignored. Details about the Forced Balance feature are explained in the Data Reconciliation Algorithm.