Dissolved Oxygen Monitoring in Stator Cooling System

[mloughrey]

I am looking for a discussion on the "best" location for mounting a dissolved oxygen monitor on a generator stator cooling system (water with low dissolved oxygen in a closed loop with make up water from a tank - as the loop is not fully sealed). The point of the dissolved oxygen monitor is to trend dissolved oxygen and thus the potential formation of copper oxides that may plug pipes or significantly reduce heat transfer. Alarms will be set at 20 ppb and 50 ppb, but I am still debating on the "best" location in the loop for its location. If anyone has experience with dissolved oxygen meters (and types of sensors best for reading dissolved oxygen in the presence of hydrogen) operating experience would be appreciated. NOTE EPRI reports have been reviewed, now I need details!

 

[abeltio]

there are limitations to the installation of the commonly known as "O2-probe"

1. minimum diameter of the pipe to install the probe and get good readings.
2. distance from the probe to the controller
3. process-wise it should be located in a place where the system is monitored without leaving any portion un-monitored. i.e. in the return header from the stator.
4. accessibility for maintenance of the probe
5. installed in a location where there are no safety limitations.

In consultation with the OEM of the "Stator Leak Monitoring System - affectionately known as SLMS" we decided to install the O2-probe in:
the last vertical run of the 6in de-ionized water collector going into the de-ionized water tank (below the tank).
This probe complements the H2 detection in the de-ionized water by the SLMS.

The construction of the probe allows to remove the probe even while the de-ionizing system is in service - so we only need a shutdown for the first installation of the probe (welding of the threaded boss).
We installed the probe there because it is very easy to access and is the last point before the water enters the tank so if there was any O2 generated in the system it will show up here.

HTH

saludos.
a.