Capacity change mechanisms

There are various ways to change the capacity of components. Capacity in this sense is the one fixed property of a component that contributes most to the plant capacity, e.g. compressor displacement, heat exchanger area etc.

Normally you modify the capacity through the basis component dialogue or for some components the plant component dialogue.

At times, you would like to modify the capacity of more than one component. To adjust a plant to a specific requirement, one strategy is to modify the capacity of all components with the same factor. For this purpose there is a menu command Edit|Capacity. By this command there is a capacity scaling of a selected component, a group of framed components or the entire plant. Note that when selecting a component for capacity scaling, all components of the same basis component type will be scaled.

You set either a scaling factor or a desired capacity. The latter option can only be specified after first having selected a plant capacity in Output|Derived quantities and then performed a calculation with a subsequent reload (File|Reload).

There is also a third way to change the capacity of a component. Press the right mouse-button in the basis component window and select Instant capacity change . A track bar appears in a separate window. Click a basis component that has a capacity type quantity. You see the name and current value of the basis component capacity quantity, and a corresponding nominal solution is calculated. By dragging the track bar or using the keyboard arrow keys (recommended), you change the capacity to a new value and the corresponding plant state is calculated.

You may see the effect of the varying capacity value in the plant layout or in one of the diagrams. If capacity viewing has been set (View|Capacities), you also see the capacity value change in the plant layout. Observe that the calculation may fail for some plants at the extreme changes. Hint: If you display an H-logP or T-S diagram, you should persistently switch off viewing of temperatures and pressures (using View|Variables). Otherwise, the display update can be too slow.

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