Is it possible for the electrolyzer voltage to rise by over 100 volts in an instant?

In this case, it’s definitely the voltmeter that is showing incorrect readings, or the voltmeter is being affected by external interference. The tank voltage is actually externally determined; it is the output of the rectifier transformer. As long as there are no gear changes, the voltage output from the secondary side of the rectifier transformer will not fluctuate significantly. This ensures that the rectifier has a reliable power supply at a stable voltage. When the rectifier is operating properly, the rectifier tubes maintain a constant current by fine-tuning the conduction angle while remaining in a state close to saturation. (According to the simple law of Ohm’s law, I=U/R, the impedance R of the cell is not a constant value, and the external voltage U is also not a constant value; however, the amplitude of their unstable fluctuations is very small.) The rectifier adjusts the conduction angle so that the voltage applied to the cell changes in accordance with variations in the cell’s impedance, resulting in a stable current. Due to the small amplitude of fluctuations, the voltage appears to be quite stable as well. ) Such large fluctuations as described by the OP can only be attributed to a malfunction in the detection and display system itself. Furthermore, since no system protection action was triggered over a period of 1–2 seconds, nor were there any changes in other variables, it can be considered an isolated incident; there is no issue with the detection or transmission processes. The most likely explanation is that the gauge observed by the person in question is faulty or subject to severe interference. Also, I’m not sure which meter the original poster is referring to – is it the display on the host computer screen or the ammeter in the control cabinet? It’s not clear whether this voltage data is used for control or merely for display. Voltage detection is straightforward to implement, as it involves making a connection across the circuit. The original poster can simply have an electrician perform the check. If multiple voltmeters show fluctuating readings simultaneously, it indicates that there’s interference or a problem in the detection and transmission process. Conversely, if only one voltmeter shows such fluctuations, then the issue lies with that particular meter alone. Cross-comparison tests can also be conducted in different regions. Voltage meters are easily affected by external electric and magnetic fields, so proper shielding and grounding are necessary. In short, it’s clear that the problem lies not with the electrolytic cells or the manufacturing process; by observing the site more closely, we will definitely figure it out. I hope that President Zhang will post an update after resolving the issue so that we can all learn from it.

This value is the total voltage of the electrolyzer, displayed on the host computer screen, and it is not used in control purposes. We control it through several sets of single-cell voltages, but these sets of single-cell voltages don’t show any significant fluctuations, which is strange

With the voltage suddenly rising to such a high level, under normal circumstances the electrolytic cell would have failed long ago, and the ion-exchange membrane would have been damaged! It must be the voltmeter that’s being interfered with! ! !

Reply to 3# Yi Nuo Zhang: Yes, the DCS system’s detection of the electrolytic cell voltage is merely for display as a reference value; it does not participate in interlocks or control. I’m not sure what type of cell the original poster is using. For Kyocera’s devices, if you choose to monitor the voltage of individual cells, Kyocera will carry out online monitoring in groups of 10 cell units each. Then, the processed signals are sent to the DCS via a data acquisition system for display; this is the E230. The signal transmitted is called EIA230-n. It provides high-level alarms but does not participate in control functions. There’s also an EM230, which is the device that outputs EDIZA230 to the DCS for interlock control. It’s a device that uses a bridge circuit to monitor significant fluctuations in the electrolytic cell voltage and trigger interlocks accordingly. Additionally, the voltage and current signals coming from the rectification control cabinet should also be transmitted to the DCS, namely EI230; these are used for display purposes only, and they do not participate in control or interlocking functions. Is this what General Manager Zhang meant—that there’s a problem with this voltage? Regardless of which voltage shows a problem, it is an issue with that voltage itself; carefully check whether the connections in the transmission lines are proper and whether there are any open circuits in the grounding system. Since the instruments on site all output current signals in the 4–20mA range, a signal exceeding 150V is definitely beyond the output range of those primary instruments; this will cause problems with both the primary and secondary instruments as well as the wiring. Good luck to you.

This post was last edited by limingshuguang on 2011-4-3 at 17:34. In our factory, it has happened that the readings are correct on the rectifier side, but incorrect on our ion membrane display; the voltage suddenly rises from 408 volts to 420 volts. The saturation levels were all good; a measurement was taken on-site at 408, and it was ultimately determined that the sensor was faulty.

Don’t worry; this kind of thing has also happened in our company. It was a problem with the instruments, and it occurred during the night shift – it was just a false alarm.

This post was last edited by limingshuguang on 2011-4-3 17:35; this could also be useful when the parameters change significantly

This post was last edited by Yinozhang on 2011-2-19 08:41. We have also encountered this situation, but in the opposite way: during thunderstorms in summer, the DCS voltage would suddenly rise to 400V (the normal value is around 516), and then it would drop back to around 516 again. The system did not shut down as a result, but the chlorine compressor and hydrogen compressor would start running suddenly or slow down abruptly. This pattern of fluctuations continued. What is the best approach in such a situation?