Safe Shutdown of System Integrators
Although electrolysis companies perform their own safety analyses, hazard analyses should be performed by system integrators to ensure safe integration with controls and integrated emergency shutdowns. Shutdown should be initiated when:
- The ventilation system is inoperable
- A hydrogen detector senses a leak[6]
- High H2-O2 gas cross-over is detected
- Fire is detected
- An out-of-bounds operational deviation occurs (water supply issues, over-pressure, low or high temperature, power supply / conditioning upset, etc.)
During emergency shutdown, the following operations should be automatically initiated:
- Isolate bulk hydrogen storage.
- Remove power from the electrolyzer, stopping hydrogen production.
- Remove power from all unclassified electrical equipment.
- Vent pressurized hydrogen to a safe location.[7]
- Ventilation system remains on.
[6] Refer to H2Tools best practices on detection for sensor placement considerations: Leak Detection
CGA G5.5, Hydrogen Vent Systems
CHS Webinar: Safety of Water Electrolysis
CSA/ANSI 22.2 No. 22734 (to be published in 2023)
EIGA Doc 154 09 E, Safe Location of Oxygen and Inert Gas Vents
EIGA Doc 211 17, Hydrogen Vent Systems for Customer Applications
IEC 61010-1, Safety requirements for electrical equipment for measurement, control, and laboratory use - Part 1: General requirements
ISO 22734, Hydrogen generators using water electrolysis — Industrial, commercial, and residential applications (current version 2019)
ISO/TR 22734-2, Hydrogen Generators Using Water Electrolysis – Part 2: Testing guidance for performing electricity grid service (to be published in 2023)