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Welcome to the Operations and Maintenance discussion forum!  This forum is meant to provide those involved in operations and maintenance activites an opportunity to discuss topics on hydrogen and fuel cell technologies.  Our goal is to facilitate collaboration and help participants find and share solutions to enable the safe operation of facilities and equipment.

shaibalghosh

Dear All,

As we all know? Turbo generators related to Coal; Gas; Nuclear are H2 cooled.
1) Since these are H2 Cooled, can we introduce small concentration of CO2 (< 5%) as a tracer gas to detect leakage of Hydrogen from turbo generators or its ancillary fittings?
2)Is there any standard practice/permissible limit of introduction of tracer gases especially CO2 which is followed by the turbine manufacturer? Similarly they suggest to buyers.
3) Is there any similar standard suggested by IEEE/IEC/VDE (I may be wrong here with this question)? If I happen to be correct please let me know he guidelines number.

Best Regards,
Shaibal Ghosh
Skype: shaibal_ghosh
Email: shaibalghosh@gmail.com

aaron.harris

Unfortunately I am not familiar with the standards surrounding applications for H2 cooling.  However, I would not consider CO2 as the best choice for leak trace gases.  Much more commonly Helium has been used as it is similar in density and size to hydrogen.  Often systems which are leak tested in nitrogen can present leaks in hydrogen, in this case it is typically assumed that the size difference of the molecules affects the ability to detect leaks.  In addition, helium specific detection equipment exists which could enable evaluation of the trace gases.

wittetg

A couple of comments:

1. Additonal CO2 be can detrimental to the performance of a generator due to additonal windage friction, therefore it is not a good choice.

2. As hydrogen is flammable is it possible to use a flamamble detector at very low levels for leakage?

3. As helium is also a very good for both leak detection and generator cooling, I would recommend investigating using small amounts of helium woudl be a better choice for leak detection if a flammable detector does not work..