Method and system for monitoring the functionality of electrolysis cells

Abstract

Method and system for monitoring the functionality of electrolysis cells for use in chlor-alkali electrolysis. The method uses the analysis of the current / voltage characteristic of the cells in relation to an AC voltage overlaid on the operating voltage

Description

[0001]The invention relates to a method for monitoring the functionality of electrolysis cells. Furthermore, the invention relates to a system for monitoring the functionality of electrolysis cells and in particular the use thereof in chlor-alkali electrolysis.[0002]The invention is directed to monitoring methods known per se for electrolysis cells, which conventionally make use of the detection of an averaged current-voltage characteristic of the cell.BACKGROUND OF THE INVENTION[0003]The monitoring of electrolysis facilities and the diagnosis of defective cells are fundamentally based on the measurement of process-relevant parameters such as temperatures, differential pressures, or also gas concentrations, but above all on the measurement of cell voltages and cell current. The cell voltage is very sensitive with respect to changes in the electrolyzes and is easily detectable, also at the individual cells.[0004]Outotec describes, in WO 2005 / 052700 A1, a monitoring system for copper ...

AI Technical Summary

Benefits of technology

The patent text talks about a small but recognizable hysteresis effect in cells that use hydrogen-developing cathodes. This effect is caused by the high capacitances in gas diffusion electrodes used in these cells. The text also explains that this hysteresis effect is not significant in cells that use oxygen depolarized cathodes.

Problems solved by technology

These can also be designed dynamically and can even be optimized on the basis of historical data and learning-capable structures, however, they do not permit the qualitative or quantitative determination of errors in individual electrodes.

If the voltage of a cell only increases slowly, however, a defect can be presumed.

The better data base is advantageous to represent the normal operating state; the difficulty of developing a good model which can image various operating states is shown to be disadvantageous.

In principle, a voltage having a harmonic wave (ripple) is applied to the fuel cell by the inverter, which also results in ripple in the current at the output of the fuel cell.

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