Mass Transfer from Water Vapor to Hydrogen

This theory rise up begin from generator seal oil vacuum type where the water content was tending to increase. The water could be source from many places, like

1. Turbine lube oil system (which contaminated with turbine gland seal) delivered to seal oil system as make up supply.
2. Seal oil vacuum pump leak from shaft seal, so wet air from circumstance is coming to inside seal oil system.
3. Hydrogen cooler where use close cooling system.

Seal oil vacuum type already describe on http://idpowerstation.blogspot.com/2009/02/seal-oil-system.html.

And the danger of high water content on generator, already describe on http://idpowerstation.blogspot.com/2013/06/water-contamination-on-h2-cooled.html


Picture below show the seal oil vacuum pump water content Unit 01 (U1) start increase trigger with differential pressure between hydrogen and seal oil, hydrogen pressure a little bit decrease or hydrogen injection flow to generator too much over shoot of pressure. Normally water content on seal oil as shown on Unit 02 (U2)




Seal oil vacuum pump water content is possible from water vapor content on lube oil which has high concentration and move to hydrogen which has low concentration. They were contact each other on space between seal ring segment and oil deflector as picture below.

Toshiba's Generator



So much contact area between hydrogen and oil, mass transfer from water vapor to hydrogen will be increase too. This possible during injection hydrogen to generator with overshoot of pressure. This contact should be maintain as low as possible by maintain differential pressure between hydrogen and oil feed.

Toshiba's Generator



The simple theory of mass transfer already be explanation on http://mechanic-info.blogspot.com/2013/06/mass-transfer.html#more. Unfortunately the diffusion coefficient of water vapor to hydrogen still not found yet.