Cell Voltage Page

The Cell Voltage Page is the main page where you make the wanted input to obtain the corresponding results concerning the cell voltage. You need other pages to define some parameters: anode dimension on the Cell Geometry Page or the voltage drops of the busbar system on the Busbars Page. You inspect intermediate values on the Bath Voltage Page or Energy Balance Page. You get an overview about the cell voltage components and energy balance details with the Haupin Diagrams.
As for other pages the light input fields receive the input from the keyboard or with the mouse by clicking into the field and by turning the mouse wheel. In the next figure, for instance, the current intensity (200kA), the current efficiency (95 %) and the cell voltage (4.2 V) are input values. AlPrg calculates the corresponding interpolar distance (anode to cathode distance: 4.8 cm), electric power consumption (840 kW) and heat loss (377 kW).

Clicking on the Show/Hide Bath Voltage Button the user displays or hides the bath voltage input field and the voltage drop of the busbars. Furthermore the user selects with the Units Combo Box the units for energy values (electric power kW, specific electric energy kWh/kg or tension V) on the Cell Voltage Page and the Energy Balance Page. See Table I and II of the theoretical part how AlPrg converts the values to these units.

Carbon/Inert Anode Button

On several pages like the Cell Voltage, Consumptions and Profitability Analysis or the Status Bar AlPrg shows the Carbon Anodes Button or Inert Anodes Button . By pressing this button the user selects how AlPrg calculates the bath voltage: either for an electrolytic cell with consumable carbon anodes or a cell with inert, non consumable anodes.
The next figure shows the results of a calculation for inert anodes. Since the cell voltage is and input value i.e. it must stay constant the corresponding values of the bath voltage and electric power are the same compared with the calculation for carbon anodes. AlPrg has changed however the interpolar distance to keep the bath and cell voltage constant. The heat loss has changed because the aluminum production with inert anodes consumes more electric energy.

Actual/Reference Current Intensity

When the current intensity changes also the voltage drops measured at the electrolytic cell will change. The idea is that the user of AlPrg enters the measured voltage drops and other parameters like the anode dimensions at the reference current values. The user chooses this reference current state by clicking with the mouse pointer into the reference current input field. He defines then the reference current value with input from the keyboard or with the mouse wheel.
He switches the to the actual current state by double clicking into reference current input field to deactivate it or by clicking once into the actual current input field to activate that field. The next figure shows what happens when the user changes from the reference current intensity = 200 kA to an actual current intensity = 210 kA. Since the current efficiency and the cell voltage are input values AlPrg has adapted the interpolar distance to keep the cell voltage at 4.2 V.

Actual/Reference Current Intensity

Input Heat Loss

The user may select all parameters as input values and AlPrg determines the values of the other parameters. A particularly interesting case is the input of the heat loss. In the cases mentioned so far AlPrg determines among other things the heat loss i.e. AlPrg evaluates the relations given in the theoretical part in a straight forward way. If however the heat loss is an input value these equations have to be evaluated so to speak in the reverse direction. If able to do this AlPrg can answer questions like: what are the cell set values if the user wants to change (increase) the current intensity and the heat loss of the cell should stay constant i.e. no change of the cell layout (thermal isolation) is necessary. The interpolar distance must be decreased from cell voltage must be decreased from 4.8 cm to 4.2 cm and the cell voltage changes correspondingly from 4.20 V to 4.12 V.

Increase Current Intensity at Constant Heat Loss

To indicate the special case of Input Heat Loss AlPrg uses a dark shade for the desactivated input fields that contain calculation results.
As the next figure shows the user may select another parameter as input, the bath voltage for instance (3.8 V). AlPrg calculates then the corresponding new interpolar distance (5.93 cm), cell voltage (4.34 V) and current intensity (184 kA).

Remark:
You enter the Input Heat Loss state (dark shaded inactive input fields) by clicking into the heat loss input field and you leave this state by DOUBLE clicking into the same field.