[ automation ] greater system throughput , provide proportional discharges to reduce emissions , and offer seat tightness up to 98 % to prevent leaks . These devices feature online pressure checks that are very simple to perform and provide peace of mind .
Hydrogen-oxygen separators
It is important to control the level in the hydrogen and oxygen separators to prevent overfills and hydrogen and oxygen gas carry-under from going to the water system . This is a challenging application , even for guided wave radar , which in general provides extremely accurate and reliable measurements . Deploying a radar with probe end projection enables accurate measurements of very low dielectric media , such as those found in this application . In addition , radar devices offering dynamic vapour compensation can eliminate accuracy errors associated with varying pressure and temperature when steam vapour is present . This functionality provides measurement certainty and ensures safe and efficient operation with optimised throughput , without the risk of overfills .
Along with providing greater process visibility , non-intrusive wireless sensors can reliably detect the hydrogen-oxygen mix , identify leaks , and flag potential maintenance issues before they lead to shutdowns . Similarly , by providing early indication of problems with water quality prior to it entering the electrolyser units , wireless sensors can prevent irreversible damage to hardware . Digital twin solutions enable engineers to virtually simulate and test new designs with real-time dashboard process mock-ups , so that flaws and opportunities for efficiency can be better understood without risking any actual impact on production .
Leak detection
It is worth noting that some of hydrogen ’ s properties make it safer to handle and use than other fuels . For example , hydrogen is non-toxic , and because it is much lighter than air , it dissipates rapidly should there be a leak . Embrittlement accentuates the possibly of leak due to damage to infrastructure or supporting equipment such as measurement or control devices . Rapid detection of leaks is very important . As with natural gas , it can be hard to identify leaks , and adding an odorant is one option to help enhance safety . However , odorants can contaminate fuels cells , so this method is not possible in all applications .
The early detection of pressurised gas releases into the atmosphere is important , but they can be difficult to detect . In general , few leaks get detected using conventional solutions , such as personal monitoring or fixed-point gas detection . These systems can also be susceptible to false alarms that can affect production availability . The deployment of ultrasonic gas leak detection , point and open-path gas detectors increases detection efficiency and provides accurate alarms , even in external applications .
Should a gas leak be ignited , locating the source of the leak quickly and shutting off the supply to that point is essential . Hydrogen burns with a flame that is almost invisible to the naked eye , but optical flamesensing technologies detect the electromagnetic radiation emitted by flames . However , the flames can be seen using UV / IR flame detectors . Speed of detection is paramount and multi-IR detectors have been developed that can detect flames up to 90 metres away in just milliseconds .
Conclusion
As the production of green hydrogen transitions from small-scale research and development pilot projects to large-scale production plants , automation and control technology has an essential role to play in ensuring safety . By providing automated safety functions and plantwide visibility to process and machinery health information , advanced automation will make it possible to operate a fleet of green hydrogen production plants autonomously and safely from a central control , maintenance , diagnostic and optimisation centre .
Hydrogen Tech World | Issue 8 | February 2023 29